Preliminary RT9602
DS9602-00 January 2002 www.richtek-ic.com.tw
1
Dual Channel Synchronous-Rectified Buck MOSFET Driver
General Description
The RT9602 is a, twin power channel MOSFET driver
specifically designed to drive four power N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. These drivers combined with a
RT9237/RT9241 series of Multi-Phase Buck PWM
controller provide a complete core voltage regulator
solution for advanced microprocessors.
The RT9602 can provide flexible gate driving for both
high side and low side drivers. This gives more
flexibility of MOSFET selection.
The output drivers in the RT9602 have the capability
to drive a 3000pF load with a 40ns propagation delay
and 80ns transition time. This device implements
bootstrapping on the upper gates with only a single
external capacitor required for each power channel.
This reduces implementation complexity and allows
the use of higher performance, cost effective, N-
Channel MOSFETs. Adaptive shoot-through
protection is integrated to prevent both MOSFETs
from conducting simultaneously.
The RT9602 can detect high side MOSFET drain-to-
source electrical short at power on and pull the 12V
power by low side MOS and cause power supply to
go into over current shutdown to prevent damage of
CPU.
Ordering Information
RT9602
Features
z Drives Four N-Channel MOSFETs
z Adaptive Shoot-Through Protection
z Internal Bootstrap Devices
z Small 14-Lead SOIC Package
z 5V to 12V Gate-Drive Voltages for Optimal
Efficiency
z Tri-State Input for Bridge Shutdown
z Supply Under-Voltage Protection
z Power ON Over-Voltage Protection
Applications
z Core Voltage Supplies for Intel Pentium 4 and
AMD AthlonTM Microprocessors
z High Frequency Low Profile DC-DC Converters
z High Current Low Voltage DC-DC Converters
Pin Configurations
Part Number Pin Configurations
RT9602CS
(Plastic SOP-14)
TOP VIEW
Operating temperature range
C: Commercial standard
Package type
S : SOP-14
1
2
3
4
5
6
7
PWM1
PWM2
GND
LGATE1
PVCC
PGND
LGATE2
VCC
PHASE1
UGATE1
BOOT1
BOOT2
UGATE2
PHASE2
14
13
12
11
10
9
8
RT9602 Preliminary
www.richtek-ic.com.tw DS9602-00 January 2002
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Pin Description
Pin No. Pin Name Pin Function
1PWM1 Channel 1 PWM Input
2PWM2 Channel 2 PWM Input
3GND Ground Pin
4LGATE1 Lower Gate Drive of Channel 1
5PVCC Upper and Lower Gate Driver Power Rail
6PGND Lower Gate Driver Ground Pin
7LGATE2 Lower Gate Drive of Channel 2
8
PHASE2
Connect this pin to phase point of channel 2.
Phase point is the connection point of high side MOSFET source and low side MOSFET drain
9UGATE2 Upper Gate Drive of Channel 2
10 BOOT2 Floating Bootstrap Supply Pin of Channel 2
11 BOOT1 Floating Bootstrap Supply Pin of Channel 1
12 UGATE1 Upper Gate Drive of Channel 1
13 PHASE1 Connect this pin to phase point of channel 1.
Phase point is the connection point of high side MOSFET source and low side MOSFET drain
14 VCC Control Logic Power Supply
Preliminary RT9602
DS9602-00 January 2002 www.richtek-ic.com.tw
3
Function Block Diagram
Shoot-through
Protection
Power-on OVP
Shoot-through
Protection
Shoot-through
Protection
Power-on OVP
Shoot-through
Protection
Control
Logic
PVCC
BOOT1
UGATE1
PHASE1
LGATE1
PGND
VCC
BOOT2
UGATE2
PHASE2
LGATE2
PVCC
PGND
PGND
Internal
5V
19K
19K
PWM1
PWM2
GND
Internal
5V
19K
19K PVCC
PVCC
RT9602 Preliminary
www.richtek-ic.com.tw DS9602-00 January 2002
4
Absolute Maximum Ratings
z Supply Voltage (VCC) 15V
z Supply Voltage (PVCC) VCC + 0.3V
z BOOT Voltage (VBOOT-VPHASE) 15V
z Input Voltage (VPWM) GND–0.3V to 7V
z UGATE VPHASE-0.3V to VBOOT+0.3V
z LGATE GND-0.3V to VPVCC+0.3V
z Package Thermal Resistance
SOP-14, θJA 160°C /W
z Ambient Temperature 0°C ~ 70°C
z Junction Temperature 0°C ~ 125°C
z Storage Temperature Range -40°C ~ 150°C
z Lead Temperature (Soldering, 10 sec.) 260°C
z ESD Level
HBM 2KV
MM 200V
Electrical Characteristics
Parameter Symbol Test Conditions Min Typ Max Units
VCC Supply Current
Bias Supply Current IVCC fPWM = 250KHz, VPVCC = 12V,
Cboot = 0.1µF, Rphase = 20Ω-- 3 -- mA
Power Supply Current IPVCC fPWM = 250kHz, VPVCC = 12V,
Cboot = 0.1µF, Rphase = 20Ω-- 8 -- mA
Power-On Reset
VCC Rising Threshold 9.1 9.6 10 V
VCC Falling Threshold 7.5 8.1 8.5 V
PWM Input
Maximum Input Current VPWM = 0 or 5V -- 200 -- µA
PWM Floating Voltage Vcc=12V -- 1.9 -- V
PWM Rising Threshold -- 3.7 -- V
PWM Falling Threshold -- 1.1 -- V
UGATE Rise Time VPVCC = VVCC = 12V, 3nF load -- 30 -- ns
LGATE Rise Time VPVCC = VVCC = 12V, 3nF load -- 30 -- ns
UGATE Fall Time VPVCC = VVCC = 12V, 3nF load -- 40 -- ns
LGATE Fall Time VPVCC = VVCC = 12V, 3nF load -- 30 -- ns
UGATE Turn-Off Propagation Delay VVCC = VPVCC = 12V, 3nF load -- 60 -- ns
LGATE Turn-Off Propagation Delay VVCC = VPVCC = 12V, 3nF load -- 45 -- ns
Shutdown Window 1.1 -- 3.7 V
To be continued
Preliminary RT9602
DS9602-00 January 2002 www.richtek-ic.com.tw
5
Parameter Symbol Test Conditions Min Typ Max Units
Output
Upper Drive Source RUGATE VVCC = 12V, VPVCC = 12V -- 1.5 -- Ω
Upper Drive Sink RUGATE VVCC = 12V, VPVCC = 12V -- 1.45 2 Ω
Lower Drive Source RLGATE VVCC = 12V, VPVCC = 12V -- 1.6 -- Ω
Lower Drive Sink RLGATE VVCC = VPVCC = 12V -- 0.75 1 Ω
Operation Descriptions
The RT9602 has power on protection function which
held UGATE and LGATE low before VCC up across
the rising threshold voltage. After the initialization, the
PWM signal takes the control. The rising PWM signal
first forces the LGATE signal turns low then UGATE
signal is allowed to go high just after a non-
overlapping time to avoid shoot-through current. The
falling of PWM signal first forces UGATE to go low.
When UGATE and PHASE signal reach a
predetermined low level, LGATE signal is allowed to
turn high. The non-overlapping function is also
presented between UGATE and LGATE signal
transient.
The PWM signal is recognized as high if above rising
threshold and as low if below falling threshold. Any
signal level in this window is considered as tri-state,
which causes turn-off of both high side and low-side
MOSFET. When PWM input is floating (not
connected), internal divider will pull the PWM to 1.9V
to give the controller a recognizable level. The
maximum sink/source capability of internal PWM
reference is 60µA.
The PVCC pin provides flexibility of both high side
and low side MOSFET gate drive voltages. If 8V, for
example, is applied to PVCC, then high side
MOSFET gate drive is 8V-1.5V(approximately,
internal diode plus series resistance voltage drop).
The low side gate drive voltage is exactly 8V.
The RT9602 implements a power on over-voltage
protection function. If the PHASE voltage exceeds
1.5V at power on, the LGATE would be turn on to pull
the PHASE low until the PHASE voltage goes below
1.5V. Such function can protect the CPU from
damage by some short condition happened before
power on, which is sometimes encountered in the
M/B manufacturing line.
RT9602 Preliminary
www.richtek-ic.com.tw DS9602-00 January 2002
6
Typical Application Circuit
1
2
3
4
5
6
7
8
9
10
15
11
18
17
16
12
20
19
VID4
VID3
VID2
VID1
VID0
COMP
FB
ADJ
DVD
SS ISN2
ISP2
ISN1
PWM2
PWM1
ISP1
PGOOD
VDD
RT9241
PGOOD
+5V
1µF
1000µF
PHB83N03LT
3K
12V
VID4
VID3
VID2
VID1
VID0
0.1µF
3K
18K
2.4K
2.4K 15K
66pF
1µF
10K
1.2µH
11
12
13
4
9
8
7
10
14
BOOT1
UGATE1
PHASE1
LGATE1
UGATE2
PHASE2
LGATE2
BOOT2
PGND
GND
PWM1
PWM2
PVCC
VCC
5
1
2
3
6
14
VSEN
13
GND
12V
12V
3K
3K
3K
10Ω
1µF
2µH
PHB95N03LT
×1500µF
1000µF1µF
2µH
×1500µF1µF
RT9602
+5V
VCORE
PHB83N03LT
PHB95N03LT
1µF
Preliminary RT9602
DS9602-00 January 2002 www.richtek-ic.com.tw
7
Package Information
Dimensions In Millimeters Dimensions In Inches
Symbol Min Max Min Max
A 8.534 8.738 0.336 0.344
B 3.810 3.988 0.150 0.157
C 1.346 1.753 0.053 0.069
D 0.330 0.508 0.013 0.020
F 1.194 1.346 0.047 0.053
H 0.178 0.254 0.007 0.010
I 0.102 0.254 0.004 0.010
J 5.791 6.198 0.228 0.244
M 0.406 1.270 0.016 0.050
14–Lead SOP Plastic Package
B
M
H
B J
A
C
I
FD
RT9602 Preliminary
www.richtek-ic.com.tw DS9602-00 January 2002
8
RICHTEK TECHNOLOGY CORP.
Headquarter
6F, No. 35, Hsintai Road, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5510047 Fax: (8863)5537749
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing)
8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek-ic.com.tw
