PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
6-A, 4.5-V to 14-V INPUT, NON-ISOLATED,
WIDE-OUTPUT, ADJUSTABLE POWER MODULE WITH TurboTrans
Check for Samples: PTH08T230W,PTH08T231W
1FEATURES
2Up to 6-A Output Current TurboTransTechnology
4.5-V to 14-V Input Voltage Designed to meet Ultra-Fast Transient
Requirements up to 300 A/µs
Wide-Output Voltage Adjust (0.69 V to 5.5 V)
SmartSync Technology
±1.5% Total Output Voltage Variation
Efficiencies up to 95% APPLICATIONS
Output Overcurrent Protection Complex Multi-Voltage Systems
(Nonlatching, Auto-Reset) Microprocessors
Operating Temperature: 40°C to 85°CBus Drivers
Safety Agency Approvals
UL/IEC/CSA-C22.2 60950-1
Prebias Startup
On/Off Inhibit
Differential Output Voltage Remote Sense
Adjustable Undervoltage Lockout
Auto-TrackSequencing
Ceramic Capacitor Version (PTH08T231W)
DESCRIPTION
The PTH08T230/231W is the higher input voltage (4.5V to 14V) version of the PTH04T230/231W (2.2V to 5.5V),
6-A rated, non-isolated power module. This regulator represents the 2nd generation of the PTH series of power
modules which include a reduced footprint and improved features. The PTH08T231W is optimized to be used in
applications requiring all ceramic capacitors.
Operating from an input voltage range of 4.5V to 14V, the PTH08T230/231W requires a single resistor to set the
output voltage to any value over the range, 0.69V to 5.5V. The wide input voltage range makes the
PTH08T230/231W particularly suitable for advanced computing and server applications that use a loosely
regulated 8-V to 12-V intermediate distribution bus. Additionally, the wide input voltage range increases design
flexibility by supporting operation with tightly regulated 5-V, 8-V, or 12-V intermediate bus architectures.
The module incorporates a comprehensive list of features. Output over-current and over-temperature shutdown
protects against most load faults. A differential remote sense ensures tight load regulation. An adjustable
under-voltage lockout allows the turn-on voltage threshold to be customized. Auto-Tracksequencing is a
popular feature that greatly simplifies the simultaneous power-up and power-down of multiple modules in a
power system.
The PTH08T230/231W includes new patent pending technologies, TurboTransand SmartSync. The
TurboTrans feature optimizes the transient response of the regulator while simultaneously reducing the quantity
of external output capacitors required to meet a target voltage deviation specification. Additionally, for a target
output capacitor bank, TurboTrans can be used to significantly improve the regulator's transient response by
reducing the peak voltage deviation. SmartSync allows for switching frequency synchronization of multiple
modules, thus simplifying EMI noise suppression tasks and reduces input capacitor RMS current requirements.
Double-sided surface mount construction provides a low profile and compact footprint. Package options include
both through-hole and surface mount configurations that are lead (Pb) - free and RoHS compatible.
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2TurboTrans, Auto-Track, TMS320 are trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date. Copyright ©20052011, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
PTH08T230W
2
4
8
+
7
Track
GND
TT
3
GND
GND
+Sense 5
L
O
A
D
−Sense
+
10
Inhibit INH/UVLO
Auto−Track
9
6
−Sense
+Sense
SYNC
1
SmartSync
TurboTrans
RTT
1%
0.05 W
(Optional)
VO
CO2
100 µF
(Required)
CO1
200 µF
Ceramic
(Required)
RSET
1%
0.05 W
(Required)
VI
VOAdj
VI
CI
330 µF
(Required)
(Notes B and C)
VO
[D]
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
PTH08T230W
A. RSET required to set the output voltage to a value higher than 0.69 V. See the Electrical Characteristics table.
B. An additional 22-μF ceramic input capacitor is recommended to reduce RMS ripple current.
C. For VIgreater than 8 V, the minimum required CImay be reduced to 220 μF plus a 22-μF ceramic capacitor.
D. 200 μF of output capacitance can be achieved by using two 100-μF ceramic capacitors or four 47-μF ceramic
capacitors.
2Copyright ©20052011, Texas Instruments Incorporated
PTH08T231W
2Vi
4
8
CI
300 uF
(Required)
7
VI Track
GND VoAdj
Vo
TT
3
GND
GND
RTT
1%
0.05W
(Optional)
+Sense 5
L
O
A
D
−Sense
10
Inhibit INH/UVLO
Auto−Track
9
6
−Sense
+Sense
Vo
SYNC
1
SmartSync
CO
200 µF
Ceramic
(Required)
TurboTrans
RSET
1%
0.05 W
(Required)
(Note A)
[B]
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
PTH08T231W - Ceramic Capacitor Version
A. RSET required to set the output voltage to a value higher than 0.69 V. See the Electrical Characteristics table.
B. 200 μF of output capacitance can be achieved by using two 100-μF ceramic capacitors or four 47-μF ceramic
capacitors.
C. 300 µF of ceramic or 330 µF of electrolytic input capacitance is required for proper operation.
D. For VIgreater than 8 V, the minimum required CImay be reduced to 200 µF ceramic or 220 μF electrolytic plus a
22-μF ceramic capacitor.
Copyright ©20052011, Texas Instruments Incorporated 3
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
ORDERING INFORMATION
For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet, or see
the TI website at www.ti.com.
DATASHEET TABLE OF CONTENTS
DATASHEET SECTION PAGE NUMBER
ENVIRONMENTAL AND ABSOLUTE MAXIMUM RATINGS 3
ELECTRICAL CHARACTERISTICS TABLE (PTH08T230W) 4
ELECTRICAL CHARACTERISTICS TABLE (PTH08T231W) 6
PIN-OUT AND TERMINAL FUNCTIONS 8
TYPICAL CHARACTERISTICS (VI= 12V) 9
TYPICAL CHARACTERISTICS (VI= 5V) 10
ADJUSTING THE OUTPUT VOLTAGE 11
CAPACITOR RECOMMENDATIONS 13
TURBOTRANSINFORMATION 17
UNDERVOLTAGE LOCKOUT (UVLO) 22
SOFT-START POWER-UP 23
OVER-CURRENT PROTECTION 23
OVER-TEMPERATURE PROTECTION 23
OUTPUT ON/OFF INHIBIT 24
REMOTE SENSE 24
SYCHRONIZATION (SMARTSYNC) 25
AUTO-TRACK SEQUENCING 26
PREBIAS START-UP 29
TAPE &REEL AND TRAY DRAWINGS 31
ENVIRONMENTAL AND ABSOLUTE MAXIMUM RATINGS
(Voltages are with respect to GND) UNIT
VTrack Track pin voltage 0.3 to VI+ 0.3 V
VSYNC SYNC pin voltage 0.3 to 6.0 V
TAOperating temperature range Over VIrange 40 to 85
Surface temperature of module body or pins
Twave Wave soldering temperature AD suffix 260
(5 seconds maximum) AS suffix 235(1) °C
Treflow Solder reflow temperature Surface temperature of module body or pins AZ suffix 260(1)
Tstg Storage temperature Storage temperature of module removed from shipping package 55 to 125
Tpkg Packaging temperature Shipping Tray or Tape and Reel storage or bake temperature 45
Mechanical shock Per Mil-STD-883D, Method 2002.3, 1 msec, 1/2 sine, mounted 500
Suffix AD 20 G
Mechanical vibration Mil-STD-883D, Method 2007.2, 20-2000 Hz Suffix AS and AZ 15
Weight 2.5 grams
Flammability Meets UL94V-O
(1) During reflow of surface mount package version do not elevate peak temperature of the module, pins or internal components above the
stated maximum.
4Copyright ©20052011, Texas Instruments Incorporated
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
ELECTRICAL CHARACTERISTICS
TA=25°C, VI= 5V, VO= 3.3V, CI= 330µF, CO1 = 200µF ceramic, CO2 = 100µF, IO= IOmax (unless otherwise stated)
PARAMETER TEST CONDITIONS PTH08T230W
MIN TYP MAX UNIT
IOOutput current Over VOrange 25°C, natural convection 0 6 A
0.69 VO1.2 4.5 14(1)
VIInput voltage range Over IOrange 1.2 <VO3.6 4.5 14 V
3.6 <VO5.5 VO+1(2) 14
Output adjust range Over IOrange 0.69 5.5 V
Set-point voltage tolerance ±1.0 (3) %Vo
Temperature variation 40°C<TA<85°C±0.25 %Vo
VOLine regulaltion Over VIrange ±3 mV
Load regulation Over IOrange ±2 mV
Total output variation Includes set-point, line, load, 40°CTA85°C±1.5 (3) %VO
RSET = 169 , VI= 8.0 V, VO= 5.0V 95%
RSET = 1.21 k, VO= 3.3 V 92%
RSET = 2.37 k, VO= 2.5 V 90%
RSET = 4.75 k, VO= 1.8 V 88%
ηEfficiency IO= 6 A RSET = 6.98 k, VO= 1.5 V 87%
RSET = 12.1 k, VO= 1.2 V 85%
RSET = 20.5 k, VO= 1.0 V 83%
RSET = 681 k, VO= 0.7 V 79%
VORipple (peak-to-peak) 20-MHz bandwidth 1(1) %VO
ILIM Overcurrent threshold Reset, followed by auto-recovery 10 A
Recovery Time 70 µSec
w/o TurboTrans
CO1 = 200 μF, ceramic VOOvershoot 150 mV
w/o TurboTrans (4) Recovery Time 100 µSec
2.5 A/µs load step CO1 = 200 μF, ceramic
Transient response 50% to 100% IOmax VOOvershoot 100 mV
CO2 = 330 μF, Type B
VO= 2.5 V with TurboTrans Recovery Time 150 µSec
CO1 = 200 μF, ceramic
CO2 = 330 μF, Type B VOOvershoot 60 mV
RTT = 11.3 k
IIL Track input current (pin 9) Pin to GND -130 (5) µA
dVtrack/dt Track slew rate capability COCO(max) 1 V/ms
VIincreasing, RUVLO = OPEN 4.3 4.45
Adjustable Under-voltage lockout
UVLOADJ VIdecreasing, RUVLO = OPEN 3.7 4.2 V
(pin 10) Hysteresis, RUVLO 52.3 k0.5
Input high voltage (VIH) Open(6) V
Inhibit control (pin 10) Input low voltage (VIL) -0.2 0.6
Input low current (IIL), Pin 10 to GND 235 µA
Iin Input standby current Inhibit (pin 10) to GND, Track (pin 9) open 5 mA
fsSwitching frequency Over VIand IOranges, SmartSync (pin 1) to GND 300 kHz
(1) For output voltages 1.2 V, at nominal operating frequency, the output ripple may increase (typically 2×) when operating at input
voltages greater than (VO×11). When using the SmartSync feature to adjust the switching frequency, see the SmartSync
Considerations section of the datasheet for further guidance.
(2) The minimum input voltage is 4.5V or (VO+1)V, whichever is greater. Additional input capacitance may be required when VI<(VO+2)V.
(3) The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a
tolerance of 1% with 100 ppm/°C or better temperature stability.
(4) Without TurboTrans, the minimum ESR limit of 7 mmust not be violated.
(5) A low-leakage (<100 nA), open-drain device, such as MOSFET or voltage supervisor device, is recommended to control pin 9. The
open-circuit voltage is less than 6.5 Vdc.
(6) This control pin has an internal pull-up. Do not place an external pull-up on this pin. If it is left open-circuit, the module operates when
input power is applied. A small, low-leakage (<100 nA) MOSFET is recommended for control. For additional information, see the related
application information section.
Copyright ©20052011, Texas Instruments Incorporated 5
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
TA=25°C, VI= 5V, VO= 3.3V, CI= 330µF, CO1 = 200µF ceramic, CO2 = 100µF, IO= IOmax (unless otherwise stated)
PARAMETER TEST CONDITIONS PTH08T230W
MIN TYP MAX UNIT
fSYNC Synchronization (SYNC) frequency 240 400 kHz
VSYNCH SYNC High-Level Input Voltage 2 5.5 V
SmartSync Control
VSYNCL SYNC Low-Level Input Voltage 0.8 V
tSYNC SYNC Minimum Pulse Width 200 nSec
CIExternal input capacitance 330 (7) µF
Nonceramic 0 (8) 100 5000 (9)
Capacitance value µF
without Ceramic 200 (8) 500
TurboTrans Equivalent series resistance (non-ceramic) 7 m
COExternal output capacitance see table 10,000
Capacitance value μF
with (10) (11)
Turbotrans Capacitance ×ESR product (CO×ESR) 1000 10,000 μF×m
Per Telcordia SR-332, 50% stress,
MTBF Reliability 6.7 106Hr
TA= 40°C, ground benign
(7) A 330 µF electrolytic input capacitor is required for proper operation. The capacitor must be rated for a minimum of 450 mA rms of ripple
current. An additional 22-μF ceramic input capacitor is recommended to reduce rms ripple current. When operating at VI>8V, the
minimum required CImay be reduced to a 220-μF electrolytic plus a 22-μF ceramic.
(8) 200 µF ceramic external output capacitance is required for basic operation. The required ceramic output capacitance can be made up of
2×100 µF or 4 ×47 µF. The minimum output capacitance requirement increases when TurboTrans(TT) technology is used. See the
Application Information for more guidance.
(9) This is the calculated maximum disregarding TurboTranstechnology. When the TurboTrans feature is used, the minimum output
capacitance must be increased. See the TurboTrans application notes for further guidance.
(10) When using TurboTranstechnology, a minimum value of output capacitance is required for proper operation. Additionally, low ESR
capacitors are required for proper operation. See the TurboTrans application notes for further guidance.
(11) This is the calaculated maximum when using the TurboTrans feature. Additionally, low ESR capacitors are required for proper operation.
See the TurboTrans application notes for further guidance.
6Copyright ©20052011, Texas Instruments Incorporated
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
ELECTRICAL CHARACTERISTICS
TA=25°C, VI= 5 V, VO= 3.3 V, CI= 330 µF, CO1 = 200 µF ceramic, and IO= IOmax (unless otherwise stated)
PARAMETER TEST CONDITIONS PTH08T231W
MIN TYP MAX UNIT
IOOutput current Over VOrange 25°C, natural convection 0 6 A
0.69 VO1.2 4.5 14 (1)
VIInput voltage range Over IOrange 1.2 <VO3.6 4.5 14 V
3.6 <VO5.5 VO+1(2) 14
Output adjust range Over IOrange 0.69 5.5 V
Set-point voltage tolerance ±1.0 (3) %Vo
Temperature variation 40°C<TA<85°C±0.25 %Vo
VOLine regulaltion Over VIrange ±3 mV
Load regulation Over IOrange ±2 mV
Total output variation Includes set-point, line, load, 40°CTA85°C±1.5 (3) %VO
RSET = 169 , VI= 8.0 V, VO= 5.0V 95%
RSET = 1.21 k, VO= 3.3 V 92%
RSET = 2.37 k, VO= 2.5 V 90%
RSET = 4.75 k, VO= 1.8 V 88%
ηEfficiency IO= 6 A RSET = 6.98 k, VO= 1.5 V 87%
RSET = 12.1 k, VO= 1.2 V 85%
RSET = 20.5 k, VO= 1.0 V 83%
RSET = 681 k, VO= 0.7 V 79%
VORipple (peak-to-peak) 20-MHz bandwidth 1(1) %VO
ILIM Overcurrent threshold Reset, followed by auto-recovery 10 A
Recovery Time 80 µSec
w/o TurboTrans
CO1 = 200 μF, ceramic VOOvershoot 85 mV
2.5 A/µs load step Recovery Time 120 µSec
w/o TurboTrans (4)
50% to 100% IOmax
Transient response CO1 = 400 μF, ceramic
VI= 12 V VOOvershoot 75 mV
VO= 3.3 V with TurboTrans Recovery Time 220 µSec
CO1 = 400 μF, ceramic VOOvershoot 45 mV
RTT = 8.06 k
IIL Track input current (pin 9) Pin to GND -130 (5) µA
dVtrack/dt Track slew rate capability COCO(max) 1 V/ms
VIincreasing, RUVLO = OPEN 4.3 4.45
Adjustable Under-voltage lockout
UVLOADJ VIdecreasing, RUVLO = OPEN 3.7 4.2 V
(pin 10) Hysteresis, RUVLO 52.3 k0.5
Input high voltage (VIH) Open(6) V
Inhibit control (pin 10) Input low voltage (VIL) -0.2 0.6
Input low current (IIL), Pin 10 to GND 235 µA
Iin Input standby current Inhibit (pin 10) to GND, Track (pin 9) open 5 mA
fsSwitching frequency Over VIand IOranges, SmartSync (pin 1) to GND 300 kHz
fSYNC Synchronization (SYNC) frequency 240 400 kHz
VSYNCH SYNC High-Level Input Voltage 2 5.5 V
SmartSync Control
VSYNCL SYNC Low-Level Input Voltage 0.8 V
tSYNC SYNC Minimum Pulse Width 200 nSec
(1) For output voltages 1.2 V, at nominal operating frequency, the output ripple may increase (typically 2×) when operating at input
voltages greater than (VO×11). When using the SmartSync feature to adjust the switching frequency, see the SmartSync
Considerations section of the datasheet for further guidance.
(2) The minimum input voltage is 4.5V or (VO+1)V, whichever is greater. Additional input capacitance may be required when VI<(VO+2)V.
(3) The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a
tolerance of 1% with 100 ppm/°C or better temperature stability.
(4) Without TurboTrans, the minimum ESR limit of 7 mmust not be violated.
(5) A low-leakage (<100 nA), open-drain device, such as MOSFET or voltage supervisor device, is recommended to control pin 9. The
open-circuit voltage is less than 6.5 Vdc.
(6) This control pin has an internal pull-up. Do not place an external pull-up on this pin. If it is left open-circuit, the module operates when
input power is applied. A small, low-leakage (<100 nA) MOSFET is recommended for control. For additional information, see the related
application information section.
Copyright ©20052011, Texas Instruments Incorporated 7
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
TA=25°C, VI= 5 V, VO= 3.3 V, CI= 330 µF, CO1 = 200 µF ceramic, and IO= IOmax (unless otherwise stated)
PARAMETER TEST CONDITIONS PTH08T231W
MIN TYP MAX UNIT
CIExternal input capacitance 300 (7) µF
without Capacitance value Ceramic 200 (8) 5000 µF
TurboTrans
COExternal output capacitance see table
Capacitance value Ceramic 5000 (10) μF
with (9)
Turbotrans Capacitance ×ESR product (CO×ESR) 100 1000 μF×m
Per Telcordia SR-332, 50% stress,
MTBF Reliability 6.7 106Hr
TA= 40°C, ground benign
(7) 300 µF of ceramic or 330 µF of electrolytic input capacitance is required for proper operation. Electrolytic capacitance must be rated for
a minimum of 450 mA rms of ripple current. An additional 22-μF ceramic input capacitor is recommended to reduce rms ripple current.
(8) 200 µF ceramic external output capacitance is required for basic operation. The required ceramic output capacitance can be made up of
2×100 µF or 4 ×47 µF. The minimum output capacitance requirement increases when TurboTrans(TT) technology is used. See the
Application Information for more guidance.
(9) When using TurboTranstechnology, a minimum value of output capacitance is required for proper operation. Additionally, low ESR
capacitors are required for proper operation. See the TurboTrans application notes for further guidance.
(10) This is the calaculated maximum when using the TurboTrans feature. Additionally, low ESR capacitors are required for proper operation.
See the TurboTrans application notes for further guidance.
8Copyright ©20052011, Texas Instruments Incorporated
1 10
9
7
6
5
43
82
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
PTH08T230/231W
(TOP VIEW)
TERMINAL FUNCTIONS
TERMINAL DESCRIPTION
NAME NO.
VI2 The positive input voltage power node to the module, which is referenced to common GND.
VO4 The regulated positive power output with respect to the GND.
This is the common ground connection for the VIand VOpower connections. It is also the 0 Vdc reference for
GND 3 the control inputs.
The Inhibit pin is an open-collector/drain, negative logic input that is referenced to GND. Applying a low level
ground signal to this input disables the modules output and turns off the output voltage. When the Inhibit control
is active, the input current drawn by the regulator is significantly reduced. If the Inhibit pin is left open-circuit, the
Inhibit and module produces an output whenever a valid input source is applied.
10
UVLO(1) This pin is also used for input undervoltage lockout (UVLO) programming. Connecting a resistor from this pin to
GND (pin 3) allows the ON threshold of the UVLO to be adjusted higher than the default value. For more
information, see the Application Information section.
A 0.05 W 1% resistor must be directly connected between this pin and pin 6 (Sense) to set the output voltage
to a value higher than 0.69 V. The temperature stability of the resistor should be 100 ppm/°C (or better). The
setpoint range for the output voltage is from 0.69 V to 5.5 V. If left open circuit, the output voltage will default to
VOAdjust 7 its lowest value. For further information, on output voltage adjustment see the related application note.
The specification table gives the preferred resistor values for a number of standard output voltages.
The sense input allows the regulation circuit to compensate for voltage drop between the module and the load.
+ Sense 5 For optimal voltage accuracy, +Sense must be connected to VO, close to the load.
The sense input allows the regulation circuit to compensate for voltage drop between the module and the load.
Sense 6 For optimal voltage accuracy, Sense must be connected to GND (pin 3), very close to the module (within 10
cm).
This is an analog control input that enables the output voltage to follow an external voltage. This pin becomes
active typically 20 ms after the input voltage has been applied, and allows direct control of the output voltage
from 0 V up to the nominal set-point voltage. Within this range the module's output voltage follows the voltage at
Track 9 the Track pin on a volt-for-volt basis. When the control voltage is raised above this range, the module regulates
at its set-point voltage. The feature allows the output voltage to rise simultaneously with other modules powered
from the same input bus. If unused, this input should be connected to VI.
NOTE: Due to the undervoltage lockout feature, the output of the module cannot follow its own input voltage
during power up. For more information, see the related application note.
This input pin adjusts the transient response of the regulator. To activate the TurboTrans feature, a 1%, 0.05 W
resistor must be connected between this pin and pin 5 (+Sense) very close to the module. For a given value of
output capacitance, a reduction in peak output voltage deviation is achieved by using this feature. If unused, this
TurboTrans8pin must be left open-circuit. The resistance requirement can be selected from the TurboTrans resistor table in
the Application Information section. External capacitance must never be connected to this pin unless the
TurboTrans resistor is a short, 0.
This input pin sychronizes the switching frequency of the module to an external clock frequency. The SmartSync
feature can be used to sychronize the switching fequency of multiple PTH08T230/231W modules, aiding EMI
SmartSync 1 noise suppression efforts. If unused, this pin should be connected to GND (pin 3). For more information, please
review the Application Information section.
(1) Denotes negative logic: Open = Normal operation, Ground = Function active
Copyright ©20052011, Texas Instruments Incorporated 9
IO OutputCurrent A
0
0.5
1.5
1
2.5
0 1 2 5 6
PowerDissipation W
PD
VO=2.5V
VO=3.3V
VO=5V
VO=1.8V
VO=1.5V
VO=1.2V
2
3 4
Efficiency %
IO OutputCurrent A
50
55
60
65
75
85
95
100
0 1 2 3 4 5 6
70
80
90
V =5V
O
VO=2.5V
VO=1.8V
VO=1.5V
VO=3.3V
VO=1.2V
I OutputCurrent A
O
V OutputVoltageRipple V (mV)
O PP
5
10
15
25
1 2 35
46
0
0
20
V =5V
O
VO=3.3V
VO=1.2V
VO=1.5V
VO=1.8V
VO=2.5V
TA AmbientTemperature C
o
IO OutputCurrent A
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6
100LFM
NatConv
V =5V
O
TA AmbientTemperature C
o
IO OutputCurrent A
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6
100LFM
NatConv
V =3.3V
O
TA AmbientTemperature C
o
IO OutputCurrent A
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6
NatConv
V =1.2V
O
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
TYPICAL CHARACTERISTICS(1) (2)
CHARACTERISTIC DATA ( VI= 12 V)
EFFICIENCY OUTPUT RIPPLE POWER DISSIPATION
vs vs vs
OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT
Figure 1. Figure 2. Figure 3.
AMBIENT TEMPERATURE AMBIENT TEMPERATURE AMBIENT TEMPERATURE
vs vs vs
OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT
Figure 4. Figure 5. Figure 6.
(1) The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 1,Figure 2, and Figure 3.
(2) The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm double-sided PCB with 2 oz. copper.
Applies to Figure 4,Figure 5 and Figure 6.
10 Copyright ©20052011, Texas Instruments Incorporated
IO OutputCurrent A
0
0.6
1.4
1.6
0 1 2 5 6
PowerDissipation W
PD
1
3 4
0.2
0.4
0.8
1.2
VO=3.3V
VO=0.7V
VO=2.5V
VO=1.2V
VO=1.5V
VO=1.8V
Efficiency %
IO OutputCurrent A
60
65
75
85
95
100
0 1 2 3 4 5 6
70
80
90
VO=2.5V
VO=1.8V
VO=3.3V
VO=1.2V
V =0.7V
O
VO=1.5V
I OutputCurrent A
O
V OutputVoltageRipple V (mV)
O PP
2
4
6
10
1 2 35
46
0
0
8
V =0.7V
O
VO=1.2V
VO=1.5V
VO=1.8V
VO=2.5V
VO=3.3V
TA AmbientTemperature C
o
IO OutputCurrent A
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6
NatConv
ALL VO
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
TYPICAL CHARACTERISTICS(1) (2)
CHARACTERISTIC DATA ( VI= 5 V)
EFFICIENCY OUTPUT RIPPLE POWER DISSIPATION
vs vs vs
OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT
Figure 7. Figure 8. Figure 9.
AMBIENT TEMPERATURE
vs
OUTPUT CURRENT
Figure 10.
(1) The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 7,Figure 8, and Figure 9.
(2) The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm double-sided PCB with 2 oz. copper.
Applies to Figure 10.
Copyright ©20052011, Texas Instruments Incorporated 11
RSET =10k xW0.69
V -0.69
O
-1.43k W
PTH08T230W
GND
GND
VoAdj
7
5
+Sense
+Sense
−Sense
−Sense
VO
VO
R
1%
SET
0.05W
3
6
4
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
APPLICATION INFORMATION
ADJUSTING THE OUTPUT VOLTAGE
The VOAdjust control (pin 7) sets the output voltage of the PTH08T230/231W. The adjustment range is 0.69 V to
5.5 V. The adjustment method requires the addition of a single external resistor, RSET, that must be connected
directly between the VOAdjust and the Sense pins. Table 1 gives the standard value of the external resistor for
a number of standard voltages, along with the actual output voltage that this resistance value provides.
For other output voltages, the required resistor value can either be calculated using the following formula, or
simply selected from the values given in Table 2.Figure 11 shows the placement of the required resistor.
(1)
Table 1. Preferred Values of RSET for Standard Output Voltages
VO(Standard) (V) RSET (Standard Value) (k) VO(Actual) (V)
5.0 (1) 0.169 5.01
3.3 1.2 3.30
2.5 2.37 2.51
1.8 4.7 1.81
1.5 6.98 1.51
1.2 (2) 12.1 1.20
1.0 (2) 20.5 1.01
0.7 (2) 681 0.70
(1) For VO>3.6 V, the minimum input voltage is (VO+ 1) V.
(2) For output voltages 1.2V, at nominal operating frequency, the output ripple may increase (typically
2×) when operating at input voltages greater than (VO×11). When using the SmartSync feature,
review the SmartSync application section for further guidance.
(1) RSET:Use a 0.05 W resistor with a tolerance of 1% and temperature stability of 100 ppm/°C (or better). Connect the
resistor directly between pins 7 and 6, as close to the regulator as possible, using dedicated PCB traces.
(2) Never connect capacitors from VOAdjust to either GND, VO, or +Sense. Any capacitance added to the VOAdjust pin
affects the stability of the regulator.
Figure 11. VOAdjust Resistor Placement
12 Copyright ©20052011, Texas Instruments Incorporated
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www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
Table 2. Output Voltage Set-Point Resistor Values
VORequired RSET () VORequired (V) RSET ()
0.70 681 k 3.00 1.54 k
0.75 113 k 3.10 1.43 k
0.80 61.9 k 3.20 1.33 k
0.85 41.2 k 3.30 1.21 k
0.90 31.6 k 3.40 1.13 k
0.95 24.9 k 3.50 1.02 k
1.00 20.5 k 3.60 931
1.10 15.4 k 3.70 866
1.20 12.1 k 3.80 787
1.30 9.88 k 3.90 715
1.40 8.25 k 4.00 649
1.50 6.98 k 4.10 590
1.60 6.04 k 4.20 536
1.70 5.36 k 4.30 475
1.80 4.75 k 4.40 432
1.90 4.22 k 4.50 383
2.00 3.83 k 4.60 332
2.10 3.40 k 4.70 287
2.20 3.09 k 4.80 249
2.30 2.87 k 4.90 210
2.40 2.61 k 5.00 169
2.50 2.37 k 5.10 133
2.60 2.15 k 5.20 100
2.70 2.00 k 5.30 66.5
2.80 1.82 k 5.40 34.8
2.90 1.69 k 5.50 4.99
Copyright ©20052011, Texas Instruments Incorporated 13
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
CAPACITOR RECOMMENDATIONS FOR THE PTH08T230/231W POWER MODULE
Capacitor Technologies
Electrolytic Capacitors
When using electrolytic capacitors, high quality, computer-grade electrolytic capacitors are recommended.
Aluminum electrolytic capacitors provide adequate decoupling over the frequency range, 2 kHz to 150 kHz,
and are suitable when ambient temperatures are above -20°C. For operation below -20°C, tantalum,
ceramic, or OS-CON type capacitors are required.
Ceramic Capacitors
Above 150 kHz the performance of aluminum electrolytic capacitors is less effective. Multilayer ceramic
capacitors have a low ESR and a resonant frequency higher than the bandwidth of the regulator. They can
be used to reduce the reflected ripple current at the input as well as improve the transient response of the
output.
Tantalum, Polymer-Tantalum Capacitors
Tantalum type capacitors may only used on the output bus, and are recommended for applications where the
ambient operating temperature is less than 0°C. The AVX TPS series and Kemet capacitor series are
suggested over many other tantalum types due to their lower ESR, higher rated surge, power dissipation,
and ripple current capability. Tantalum capacitors that have no stated ESR or surge current rating are not
recommended for power applications.
Input Capacitor (Required)
The PTH08T231W requires a minimum input capacitance of 300 μF of ceramic type. (330 μF of electrolytic input
capacitance may also be used. See the following paragraph for the required electrolytic capacitor ratings.)
The PTH08T230W requires a minimum input capacitance of 330 μF. The ripple current rating of the capacitor
must be at least 450 mArms. An optional 22-μF X5R/X7R ceramic capacitor is recommended to reduce the RMS
ripple current. When operating with an input voltage greater than 8 V, the minimum required input capacitance
may be reduced to a 220-μF electrolytic plus a 22-μF ceramic.
Input Capacitor Information
The size and value of the input capacitor is determined by the converters transient performance capability. This
minimum value assumes that the converter is supplied with a responsive, low inductance input source. This
source should have ample capacitive decoupling, and be distributed to the converter via PCB power and ground
planes.
Ceramic capacitors should be located as close as possible to the module's input pins, within 0.5 inch (1,3 cm).
Adding ceramic capacitance is necessary to reduce the high-frequency ripple voltage at the module's input. This
will reduce the magnitude of the ripple current through the electroytic capacitor, as well as the amount of ripple
current reflected back to the input source. Additional ceramic capacitors can be added to further reduce the RMS
ripple current requirement for the electrolytic capacitor.
Increasing the minimum input capacitance to 680 µF is recommended for high-performance applications, or
wherever the input source performance is degraded.
The main considerations when selecting input capacitors are the RMS ripple current rating, temperature stability,
and less than 100 mof equivalent series resistance (ESR).
Regular tantalum capacitors are not recommended for the input bus. These capacitors require a recommended
minimum voltage rating of 2 ×(maximum dc voltage + ac ripple). This is standard practice to ensure reliability.
No tantalum capacitors were found with a sufficient voltage rating to meet this requirement.
When the operating temperature is below 0°C, the ESR of aluminum electrolytic capacitors increases. For these
applications, OS-CON, poly-aluminum, and polymer-tantalum types should be considered.
14 Copyright ©20052011, Texas Instruments Incorporated
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
Output Capacitor (Required)
The PTH08T231W requires a minimum output capacitance of 200 μF of ceramic type.
The PTH08T230W requires a minimum output capacitance of 200 μF ceramic type. An optional 100 μF of
non-ceramic, low-ESR capacitance is recommended for improved performance. See the Electrical
Characteristics table for maximum capacitor limits.
The required capacitance above the minimum will be determined by actual transient deviation requirements. See
the TurboTrans Technology application section within this document for specific capacitance selection.
Output Capacitor Information
When selecting output capacitors, the main considerations are capacitor type, temperature stability, and ESR.
When using the TurboTrans feature, the capacitance x ESR product should also be considered (see the following
section).
Ceramic output capacitors added for high-frequency bypassing should be located as close as possible to the
load to be effective. Ceramic capacitor values below 10 μF should not be included when calculating the total
output capacitance value.
When the operating temperature is below 0°C, the ESR of aluminum electrolytic capacitors increases. For these
applications, OS-CON, poly-aluminum, and polymer-tantalum types should be considered.
TurboTrans Output Capacitance
TurboTrans allows the designer to optimize the output capacitance according to the system transient design
requirement. High quality, ultra-low ESR capacitors are required to maximize TurboTrans effectiveness. When
using TurboTrans, the capacitor's capacitance (in μF) ×ESR (in m) product determines its capacitor type; Type
A, B, or C. These three types are defined as follows:
Type A = (100 capacitance ×ESR 1000) (e.g. ceramic)
Type B = (1000 <capacitance ×ESR 5000) (e.g. polymer-tantalum)
Type C = (5000 <capacitance ×ESR 10,000) (e.g. OS-CON)
When using more than one type of output capacitor, select the capacitor type that makes up the majority of your
total output capacitance. When calculating the C ×ESR product, use the maximum ESR value from the capacitor
manufacturer's data sheet.
Working Examples:
A capacitor with a capacitance of 330 μF and an ESR of 5 m, has a C ×ESR product of 1650 μFxm(330 ×
5). This is a Type B capacitor. A capacitor with a capacitance of 1000 μF and an ESR of 8 m, has a C ×ESR
product of 8000 μFxm(1000 ×8). This is a Type C capacitor.
See the TurboTrans Technology application section within this document for specific capacitance selection.
Table 3 includes a preferred list of capacitors by type and vendor. See the Output Bus / TurboTrans column.
Non-TurboTrans Output Capacitance
If the TurboTrans feature is not used, minimum ESR and maximum capacitor limits must be followed. System
stability may be effected and increased output capacitance may be required without TurboTrans.
When using the PTH08T230W without the TurboTrans feature, observe the minimum ESR of the entire output
capacitor bank. The minimum ESR limit of the output capacitor bank is 7 m. A list of preferred low-ESR type
capacitors, are identified in Table 3. Large amounts of capacitance may reduce system stability when not using
the TurboTrans feature.
When using the PTH08T231W without the TurboTrans feature, the maximum amount of capacitance is 5000 μF
of ceramic type. Large amounts of capacitance may reduce system stability.
Using the TurboTrans feature improves system stability, improves transient response, and reduces the
amount of output capacitance required to meet system transient design requirements.
Copyright ©20052011, Texas Instruments Incorporated 15
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
Designing for Fast Load Transients
The transient response of the dc/dc converter has been characterized using a load transient with a di/dt of
2.5 A/μs. The typical voltage deviation for this load transient is given in the Electrical Characteristics table using
the minimum required value of output capacitance. As the di/dt of a transient is increased, the response of a
converters regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent
limitation with any dc/dc converter once the speed of the transient exceeds its bandwidth capability.
If the target application specifies a higher di/dt or lower voltage deviation, the requirement can only be met with
additional low ESR ceramic capacitor decoupling. Generally, with load steps greater than 100 A/μs, adding
multiple 10 μF ceramic capacitors plus 10 ×1μF, and numerous high frequency ceramics (0.1 μF) is all that is
required to soften the transient higher frequency edges. The PCB location of these capacitors in relation to the
load is critical. DSP, FPGA and ASIC vendors identify types, location and amount of capacitance required for
optimum performance. Low impedance buses, unbroken PCB copper planes, and components located as close
as possible to the high frequency devices are essential for optimizing transient performance.
Table 3. Input/Output Capacitors(1)
Capacitor Characteristics Quantity
Max Output Bus (2)
Max.
Capacitor Vendor, Ripple
Working Value ESR Physical Input
Type Series (Style) No Turbo-
Current Vendor Part No.
Voltage (µF) at 100 Size (mm) Bus Turbo- Trans
at 85°C
kHz Trans Cap Type(3)
(Irms)
Panasonic
FC (Radial) 25 V 1000 43m1690mA 16 ×15 1 2 N/R(4) EEUFC1E102S
FC (Radial) 25 V 820 38m1655mA 12 ×20 1 1 N/R(4) EEUFC1E821S
FC (SMD) 35 V 470 43m1690mA 16 ×16,5 1 1 N/R(4) EEVFC1V471N
FK (SMD) 35 V 1000 35m1800mA 16 ×16,5 1 2 N/R(4) EEVFK1V102M
United Chemi-Con
PTB, Poly-Tantalum(SMD) 6.3 V 330 25m2600mA 7,3×4,3×2.8 N/R(5) 1 ~ 4 C 2(6) 6PTB337MD6TER (VO5.1V)(7)
LXZ, Aluminum (Radial) 35 V 680 38m1660mA 12,5 ×20 1 1 ~ 3 N/R(4) LXZ35VB681M12X20LL
PS, Poly-Alum (Radial) 16 V 330 14m5060mA 10 ×12,5 1 1 ~ 3 B 2(6) 16PS330MJ12
PS, Poly-Alum (Radial) 6.3 V 390 12m5500mA 8 ×12,5 N/R(5) 1 ~ 2 B 1(6) 6PS390MH11 (VO5.1V)(7)
PXA, Poly-Alum (SMD) 16 V 330 14m5050mA 10 ×12,2 1 1 ~ 3 B 2(6) PXA16VC331MJ12TP
PXA, Poly-Alum (Radial) 10 V 330 14m4420mA 8 ×12,2 N/R(5) 1 ~ 2 B 1(6) PXA10VC331MH12
Nichicon, Aluminum
PM (Radial) 25 V 1000 43m1520mA 18 ×15 1 2 N/R(4) UPM1E102MHH6
HD (Radial) 35 V 470 23m1820mA 10 ×20 1 2 N/R(4) UHD1V471HR
Panasonic, Poly-Aluminum 2.0 V 390 5m4000mA 7,3×4,3×4,2 N/R(5) N/R(8) B2(6) EEFSE0J391R(VO1.6V)(7)
(1) Capacitor Supplier Verification
Please verify availability of capacitors identified in this table. Capacitor suppliers may recommend alternative part numbers because of
limited availability or obsolete products.
RoHS, Lead-free and Material Details
See the capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process requirements.
Component designators or part number deviations can occur when material composition or soldering requirements are updated.
(2) Additional output capacitance must include the required 200 μF of ceramic type.
(3) Required capacitors with TurboTrans. See the TurboTrans Application information for Capacitor Selection
Capacitor Types:
(a) Type A = (100 <capacitance ×ESR 1000)
(b) Type B = (1,000 <capacitance ×ESR 5,000)
(c) Type C = (5,000 <capacitance ×ESR 10,000)
(4) Aluminum Electrolytic capacitor not recommended for the TurboTrans due to higher ESR ×capacitance products. Aluminum and higher
ESR capacitors can be used in conjunction with lower ESR capacitance.
(5) N/R Not recommended. The voltage rating does not meet the minimum operating limits.
(6) Required capacitors with TurboTrans. See the TurboTrans Application information for Capacitor Selection
Capacitor Types:
(a) Type A = (100 <capacitance ×ESR 1000)
(b) Type B = (1,000 <capacitance ×ESR 5,000)
(c) Type C = (5,000 <capacitance ×ESR 10,000)
(7) The voltage rating of this capacitor only allows it to be used for output voltage that is equal to or less than 80% of the working voltage.
(8) N/R Not recommended. The ESR value of this capacitor is below the required minimum when not using TurboTrans.
16 Copyright ©20052011, Texas Instruments Incorporated
PTH08T230W, PTH08T231W
www.ti.com
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
Table 3. Input/Output Capacitors(1) (continued)
Capacitor Characteristics Quantity
Max Output Bus (2)
Max.
Capacitor Vendor, Ripple
Working Value ESR Physical Input
Type Series (Style) No Turbo-
Current Vendor Part No.
Voltage (µF) at 100 Size (mm) Bus Turbo- Trans
at 85°C
kHz Trans Cap Type(3)
(Irms)
Sanyo
TPE, Poscap (SMD) 10 V 330 25m3300mA 7,3×4,3 N/R(9) 1 ~ 3 C 1(10) 10TPE330MF(11)
TPE, Poscap (SMD) 2.5 V 470 7m4400mA 7,3×4,3 N/R(9) 1 ~ 2 B 2(10) 2R5TPE470M7(VO1.8V)(11)
TPD, Poscap (SMD) 2.5 V 1000 5m6100mA 7,3×4,3 N/R(9) N/R(12) B1(10) 2R5TPD1000M5(VO1.8V)(11)
SEP, OS-CON (Radial) 16 V 330 16m4700mA 10 ×13 1 1 ~ 2 B 1(10) 16SEP330M
SEPC, OS-CON (Radial) 16 V 470 10m6100mA 10 ×13 1 1 ~ 2 B 2(10) 16SEPC470M
SVP, OS-CON (SMD) 16 V 330 16m4700mA 10 ×12,6 1 1 ~ 2 B 1(10) 16SVP330M
AVX, Tantalum
TPM Multianode 10 V 330 23m3000mA 7,3×4,3×4,1 N/R(9) 1 ~ 3 C 2(10) TPME337M010R0035
TPS Series III (SMD) 10 V 330 40m1830mA 7,3×4,3×4,1 N/R(9) 1 ~ 6 N/R(13) TPSE337M010R0040 (VO5V)(14)
TPS Series III (SMD) 4 V 1000 25m2400mA 7,3×6,1×3.5 N/R(9) 1 ~ 5 N/R(13) TPSV108K004R0035 (VO2.1V)(14)
Kemet, Poly-Tantalum
T520 (SMD) 10 V 330 25m2600mA 7,3×4,3×4,1 N/R(9) 1 ~ 3 C 2(10) T520X337M010ASE025(11)
T530 (SMD) 6.3 V 330 15m3800mA 7,3×4,3×4,1 N/R(9) 2 ~ 3 B 2(10) T530X337M010ASE015(11)
T530 (SMD) 4 V 680 5m7300mA 7,3×4,3×4,1 N/R(9) N/R(12) B1(10) T530X687M004ASE005 (VO3.5V)(11)
T530 (SMD) 2.5 V 1000 5m7300mA 7,3×4,3×4,1 N/R(9) N/R(12) B1(10) T530X108M2R5ASE005 (VO2.0V)(11)
Vishay-Sprague
597D, Tantalum (SMD) 10 V 330 35m2500mA 7,3×5,7×4,1 N/R(9) 1 ~ 5 N/R(13) 597D337X010E2T
94SA, OS-CON (Radial) 16 V 470 20m6080mA 12 ×22 1 1 ~ 3 C 2(10) 94SA477X0016GBP
94SVP OS-CON(SMD) 16 V 330 17m4500mA 10 ×12,7 2 2 ~ 3 C 1(10) 94SVP337X06F12
Kemet, Ceramic X5R 16 V 10 2m 3225 1 1(15) A(10) C1210C106M4PAC
(SMD) 6.3 V 47 2mN/R(9) 1(15) A(10) C1210C476K9PAC
Murata, Ceramic X5R 6.3 V 100 2m 3225 N/R(9) 1(15) A(10) GRM32ER60J107M
(SMD) 6.3 V 47 N/R(9) 1(15) A(10) GRM32ER60J476M
25 V 22 1 1(15) A(10) GRM32ER61E226K
16 V 10 1 1(15) A(10) GRM32DR61C106K
TDK, Ceramic X5R 6.3 V 100 2m 3225 N/R(9) 1(15) A(10) C3225X5R0J107MT
(SMD) 6.3 V 47 N/R(9) 1(15) A(10) C3225X5R0J476MT
16 V 10 1 1(15) A(10) C3225X5R1C106MT0
16 V 22 1 1(15) A(10) C3225X5R1C226MT
(9) N/R Not recommended. The voltage rating does not meet the minimum operating limits.
(10) Required capacitors with TurboTrans. See the TurboTrans Application information for Capacitor Selection
Capacitor Types:
(a) Type A = (100 <capacitance ×ESR 1000)
(b) Type B = (1,000 <capacitance ×ESR 5,000)
(c) Type C = (5,000 <capacitance ×ESR 10,000)
(11) The voltage rating of this capacitor only allows it to be used for output voltage that is equal to or less than 80% of the working voltage.
(12) N/R Not recommended. The ESR value of this capacitor is below the required minimum when not using TurboTrans.
(13) Aluminum Electrolytic capacitor not recommended for the TurboTrans due to higher ESR ×capacitance products. Aluminum and higher
ESR capacitors can be used in conjunction with lower ESR capacitance.
(14) The voltage rating of this capacitor only allows it to be used for output voltage that is equal to or less than 50% of the working voltage.
(15) Any combination of ceramic capacitor values is limited as listed in the Electrical Characteristics table.
Copyright ©20052011, Texas Instruments Incorporated 17
PTH08T230W, PTH08T231W
SLTS265L NOVEMBER 2005REVISED AUGUST 2011
www.ti.com
TURBOTRANS
TurboTransTechnology
TurboTrans technology is a feature introduced in the T2 generation of the PTH/PTV family of power modules.
TurboTrans optimizes the transient response of the regulator with added external capacitance using a single
external resistor. Benefits of this technology include reduced output capacitance, minimized output voltage
deviation following a load transient, and enhanced stability when using ultra-low ESR output capacitors. The
amount of output capacitance required to meet a target output voltage deviation will be reduced with TurboTrans
activated. Likewise, for a given amount of output capacitance, with TurboTrans engaged, the amplitude of the
voltage deviation following a load transient will be reduced. Applications requiring tight transient voltage
tolerances and minimized capacitor footprint area will benefit greatly from this technology.
TurboTransSelection
Using TurboTrans requires connecting a resistor, RTT, between the +Sense pin (pin 5) and the TurboTrans pin
(pin 8). The value of the resistor directly corresponds to the amount of output capacitance required. All T2
products require a minimum value of output capacitance whether or not TurboTrans is used. For the
PTH08T230W, the minimum required capacitance is 200 μF. When using TurboTrans, capacitors with a
capacitance ×ESR product below 10,000 μF×mare required. (Multiply the capacitance (in μF) by the ESR (in
m) to determine the capacitance ×ESR product.) See the Capacitor Selection section of the datasheet for a
variety of capacitors that meet this criteria.
Figure 12 through Figure 17 show the amount of output capacitance required to meet a desired transient voltage
deviation with and without TurboTrans for several capacitor types; Type A (e.g. ceramic), Type B (e.g.
polymer-tantalum), and Type C (e.g. OS-CON). To calculate the proper value of RTT, first determine your
required transient voltage deviation limits and magnitude of your transient load step. Next, determine what type
of output capacitors will be used. (If more than one type of output capacitor is used, select the capacitor type that
makes up the majority of your total output capacitance). Knowing this information, use the chart in Figure 12
through Figure 17 that corresponds to the capacitor type selected. To use the chart, begin by dividing the
maximum voltage deviation limit (in mV) by the magnitude of your load step (in Amps). This gives a mV/A value.
Find this value on the Y-axis of the appropriate chart. Read across the graph to the 'With TurboTrans' plot. From
this point, read down to the X-axis which lists the minimum required capacitance, CO, to meet that transient
voltage deviation. The required RTT resistor value can then be calculated using the equation or selected from the
TurboTrans table. The TurboTrans tables include both the required output capacitance and the corresponding
RTT values to meet several values of transient voltage deviation for 25% (1.5 A), 50% (3 A), and 75% (4.5 A)
output load steps.
The chart can also be used to determine the achievable transient voltage deviation for a given amount of output
capacitance. Selecting the amount of output capacitance along the X-axis, reading up to the 'With TurboTrans'
curve, and then over to the Y-axis, gives the transient voltage deviation limit for that value of output capacitance.
The required RTT resistor value can be calculated using the equation or selected from the TurboTrans table.
As an example, let's look at a 12-V application requiring a 45 mV deviation during an 3 A, 50% load transient. A
majority of 330 μF, 10 mouput capacitors are used. Use the 12 V, Type B capacitor chart, Figure 14. Dividing
45 mV by 3 A gives 15 mV/A transient voltage deviation per amp of transient load step. Select 15 mV/A on the
Y-axis and read across to the 'With TurboTrans' plot. Following this point down to the X-axis gives us a minimum
required output capacitance of approximately 850 μF. The required RTT resistor value for 850 μF can then be
calculated or selected from Table 5. The required RTT resistor is 1.82 kΩ.
To see the benefit of TurboTrans, follow the 15 mV/A marking across to the 'Without TurboTrans' plot. Following
that point down shows that you would need a minimum of 4000 μF of output capacitance to meet the same
transient deviation limit. This is the benefit of TurboTrans. A typical TurboTrans schematic is shown in Figure 18.
18 Copyright ©20052011, Texas Instruments Incorporated