AVAILABLE
EVALUATION KIT AVAILABLE
Functional Diagrams
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
_______________General Description
The MAX710/MAX711 integrate a step-up DC-DC con-
verter with a linear regulator to provide step-up/down
voltage conversion. They are optimized for battery
applications where the input varies above and below
the regulated output voltage. They have an input range
from +1.8V to +11V. Typical efficiency when boosting
battery inputs is 85%.
The MAX710/MAX711 can be configured for minimum
noise or optimum efficiency. Shutdown control turns off
the part completely, disconnecting the input from the
output (ISHDN = 0.2µA). Standby control turns off only
the step-up converter and leaves the low-power linear
regulator active (IQ= 7µA).
The MAX710 has a preset 3.3V or 5V output voltage.
The MAX711 has an adjustable output that can be set
from +2.7V to +5.5V with two resistors. Both devices
come in 16-pin narrow SO packages.
________________________Applications
Single-Cell, Lithium-Powered Portable Devices
Digital Cameras
2- to 4-Cell AA Alkaline Hand-Held Equipment
3.3V and Other Low-Voltage Systems
2-, 3-, and 4-Cell Battery-Powered Equipment
Battery-Powered Devices with AC Input Adapters
____________________________Features
♦Step-Up/Down Voltage Conversion
♦+1.8V to +11V Input Range
♦Output:
5V/250mA at VIN = 1.8V
5V/500mA at VIN = 3.6V
♦No External FETs Required
♦Load Disconnected from Input in Shutdown
♦Battery Drain:
200µA No-Load (VIN = 4V)
7µA in Standby
0.2µA when Off
♦Low-Noise and High-Efficiency Modes
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
LX LX
PGND
GND
REF
PS
LBI+
LBI-
OUT
TOP VIEW
MAX710
MAX711
SO
PGND
ILIM
3/5 (FB)
SHDN
STBY
N/E
LBO
( ) IS FOR THE MAX711.
__________________Pin Configuration
MAX710
LBI+ LBO
N/E
SHDN
OFF
ON
STBY
3/5
LBI-
REF PGND
C3
0.1µF
GND ILIM
LX
PS
C4
C1
C2
L1
OUTPUT
3.3V/5V
+1.8V TO +11V
INPUT
OUT
5V
3.3V
ON
STBY
__________Typical Operating Circuit
19-1254; Rev 0; 7/97
PART
MAX710C/D
MAX710ESE
MAX711C/D 0°C to +70°C
-40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
Dice
16 Narrow SO
Dice
______________Ordering Information
MAX711ESE -40°C to +85°C 16 Narrow SO
MAX710/MAX711
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VPS = 5.6V, STBY = PS, CREF = 0.1µF, COUT = 4.7µF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at
TA= +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
PS, LX, OUT to GND............................................-0.3V to +11.5V
ILIM, SHDN, STBY, FB, 3/5, N/E, LBO,
LBI-, LBI+, REF to GND...........................-0.3V to (VPS + 0.3V)
PGND to GND .......................................................-0.3V to +0.3V
REF Short Circuit to GND...........................................Continuous
IOUT...................................................................................700mA
Continuous Power Dissipation (TA= +70°C)
SO (derate 8.70mW/°C above +70°C)..........................696mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10sec).............................+300°C
ILIM = GND
ILIM = PS
VLX = 5.6V
MAX711, VPS = 2.7V
MAX710, VPS = 3.7V
VSTBY = 0V, linear regulator
VPS = 5.6V
FB = 1.25V
TA= -40°C to +85°C, IREF = 0
TA= 0°C to +85°C, IREF = 0
MAX711
VSTBY = VSHDN = logic high, current measured
into PS pin; ILOAD = 0
VSTBY = 0V
VSHDN = 0V
MAX711, OUT = FB
CONDITIONS
A
1.1 1.5 1.95
LX Current Limit 0.5 0.8 1.3 µA0.1 1LX Leakage Current
Ω
0.6 1.2
LX On-Resistance 0.3 0.9
0.2 0.6 nA1 50FB Input Current
mV
1.18 1.25 1.31
FB Voltage
V0.9Full Load Start-Up Voltage
1.20 1.25 1.29 mA10Standby Output Current
V
1.23 1.28 1.32
Reference Voltage 1.24 1.28 1.31
VFB 5.5Output Voltage-Adjustment Range
µA100 140Quiescent Current
µA7 16Standby Quiescent Current µA0.1 5Shutdown Quiescent Current
UNITSMIN TYP MAXPARAMETER
TA= 0°C to +85°C
TA= -40°C to +85°C
0mA ≤ILOAD
≤250mA
MAX711, OUT = FB %0.1 1Load Regulation
3/5= low,
IOUT = 0 to 250mA V
4.8 5.0 5.2TA= 0°C to +85°C 4.6 5.0 5.3TA= -40°C to +85°C
3/5= high, IOUT = 0 to
250mA, VPS = 4.7V 3.17 3.3 3.43TA= 0°C to +85°C 3.05 3.3 3.55TA= -40°C to +85°C
Output Voltage (MAX710)
0 < IOUT < 250mA, STBY = PS %0.5Output Voltage Load Regulation
STBY = PS, 1.8V to 5V %/V0.3Output Voltage Line Regulation
N/E= GND (Note 2)
N/E = PS V
1.8 7.0
1.8 11.0
Input Voltage
2
Maxim Integrated
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
ELECTRICAL CHARACTERISTICS (continued)
(VPS = 5.6V, STBY = PS, CREF = 0.1µF, COUT = 4.7µF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at
TA= +25°C.) (Note 1)
Note 1: Specifications at -40°C are guaranteed by design, not production tested.
Note 2: Guaranteed by design (see Table 1).
Note 3: The LBO comparator provides the correct result as long as one input is within the specified input range.
STBY, SHDN, N/E, 3/5, ILIM
STBY = PS
CONDITIONS
V0.4Input Low Voltage
°C150Thermal Shutdown
UNITSMIN TYP MAXPARAMETER
STBY, SHDN, N/E, 3/5, ILIM
STBY, SHDN, N/E, 3/5, ILIM
(Note 3)
VLBI-, VLBI+ = 1.25V mV6 40 100Hysteresis
V1.6Input High Voltage nA1 50Input Bias Current
V1.2 10Input Range LBI-, LBI+ nA1 50Input Bias Current LBI-, LBI+
VLBI- = 1.25V
ILBO = 2mA, VLBI- = 1.25V, VLBI+ = 1V
ILBO = -300µA, VLBI- = 1.25V, VLBI+ = 2V
mV-25 +25LBI/LBO Offset Voltage 0.4 V
VPS - 0.2V
LBO Output Voltage
VOUT = 5.0V Ω
0.7 1.3
Output PFET Resistance
VPS = 3V, VOUT = 0V µA0.4 3Output PFET Leakage MAX711, VOUT = 2.7V 1.6 3.0
MAX710, VOUT = 3.0V 1.3 2.4
STBY = PS °C20Thermal Shutdown Hysteresis
LOGIC
LBI/LBO COMPARATOR
MAX710/MAX711
Maxim Integrated
3
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
90
50 0.1 10 10001 100
EFFICIENCY vs. LOAD CURRENT—
HIGH-EFFICIENCY AND LOW-NOISE MODES
(VOUT = 5V)
60
MAX710/711 TOC04
LOAD CURRENT (mA)
EFFICIENCY (%)
70
80
VOUT = 5V
VIN = 2.5V
N/E = GND
N/E = PS
ILIM = 0.8A
ILIM = 1.5A
60
10 0.01 101 10000.1 100
LINEAR-REGULATOR POWER-SUPPLY
REJECTION RATIO vs. FREQUENCY
20
MAX710/711 TOC08
FREQUENCY (kHz)
PSRR (dB)
30
40
50
55
15
25
35
45
90
50 0.1 10 10001 100
EFFICIENCY vs. LOAD CURRENT—
HIGH-EFFICIENCY AND LOW-NOISE MODES
(VOUT = 3.3V)
60
MAX710/711 TOC05
LOAD CURRENT (mA)
EFFICIENCY (%)
70
80
VOUT = 3.3V
VIN = 2.5V
ILIM = 0.8A
ILIM = 0.8A
ILIM = 1.5A
LOW-NOISE MODE
HIGH-EFFICIENCY MODE
ILIM = 1.5A
0
200
600
800
400
1200
1400
1000
1600
0 42 6 8 10 12
NO-LOAD BATTERY CURRENT
vs. INPUT VOLTAGE
MAX710/711 TOC06
INPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
N/E = GND
ILIM = GND (1.5A)
ILIM = PS (0.8A)
0
0.2
0.6
0.4
0.8
1.0
1 3 4 52 6 87 9 10 11
SHUTDOWN CURRENT
vs. INPUT VOLTAGE
MAX710/711 TOC09
INPUT VOLTAGE (V)
SHUTDOWN CURRENT (µA)
1000
10 1.0 1.4 2.2 2.6
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
100
MAX710/711 TOC07
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
1.81.2 2.01.6 2.4
ILIM = GND
ILIM = PS
N/E = GND
N/E = PS
90
50 0.1 10 10001 100
EFFICIENCY vs. OUTPUT CURRENT—
HIGH-EFFICIENCY MODE
(VOUT = 5V)
60
MAX710/711 TOC01
OUTPUT CURRENT (mA)
EFFICIENCY (%)
70
80
VIN = 1V VOUT = 5V
N/E = GND
VIN = 3.6V
VIN = 2.5V
VIN = 5.6V
VIN = 1.8V
90
50 0.1 10 10001 100
EFFICIENCY vs. OUTPUT CURRENT—
HIGH-EFFICIENCY MODE
(VOUT = 3.3V)
60
MAX710/711 TOC02
OUTPUT CURRENT (mA)
EFFICIENCY (%)
70
80
VOUT = 3.3V
N/E = GND
VIN = 2.5V
VIN = 1V
VIN = 1.8V
0
0.6
0.4
0.2
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 10050 150 200 250
MINIMUM START-UP INPUT VOLTAGE
vs. LOAD CURRENT
MAX710/711 TOC03
LOAD CURRENT (mA)
INPUT VOLTAGE (V)
VOUT = 5V
N/E = PS
4
Maxim Integrated
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
LINE-TRANSIENT RESPONSE
A
B
MAX710/711 TOC10
A: VOUT = 3.3V (100mV/div, AC COUPLED), N/E = GND
B: VIN = 2V TO 4V, IOUT = 100mA
2ms/div
A: VOUT = 3.3V (50mV/div, AC COUPLED), N/E = PS
B: IOUT = 10mA TO 100mA
LOAD-TRANSIENT RESPONSE
A
B
MAX710/711 TOC11
1ms/div
VIN = 2.5V, IOUT = 20mA, N/E = GND
VOUT = 5V (20mV/div, AC COUPLED), IOUT = 20mA
200µs/div
OUTPUT RIPPLE (HIGH-EFFICIENCY MODE)
MAX710/711 TOC12
VIN = 2.5V, IOUT = 20mA, N/E = PS
VOUT = 5V (20mV/div, AC COUPLED), IOUT = 20mA
OUTPUT RIPPLE (LOW-NOISE MODE)
MAX710/711 TOC13
200µs/div
A: VOUT (2V/div), IOUT = 100mA
B: VSHDN (2V/div)
START-UP DELAY
A
B
MAX710/711 TOC14
20µs/div
A: VOUT (2V/div), IOUT = 100mA
B: VSHDN (2V/div)
TURN-OFF DELAY
A
B
MAX710/711 TOC15
200µs/div
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX710/MAX711
Maxim Integrated
5
_______________Detailed Description
The MAX710/MAX711 integrate a step-up DC-DC con-
verter with a linear regulator to provide step-up/down
voltage conversion. The step-up switch-mode regulator
contains an N-channel power MOSFET switch. It also
shares a precision voltage reference with a linear regu-
lator that contains a P-channel MOSFET pass element
(Figure 1).
Step-Up Operation
A pulse-frequency-modulation (PFM) control scheme
with a constant 1µs off-time and variable on-time con-
trols the N-channel MOSFET switch. The N-channel
switch turns off when the part reaches the peak current
limit or the 4µs maximum on-time. The ripple frequency
is a function of load current and input voltage.
Step-Down Operation
The low-dropout linear regulator consists of a refer-
ence, an error amplifier, and a P-channel MOSFET. The
reference is connected to the error amplifier’s inverting
input. The error amplifier compares this reference with
the selected feedback voltage and amplifies the differ-
ence. The difference is conditioned and applied to the
P-channel pass transistor’s gate.
Operating Configurations
The MAX710/MAX711 have several operating configu-
rations to minimize noise and optimize efficiency for dif-
ferent input voltage ranges. These configurations are
accomplished via the N/Einput, which controls opera-
tion of the on-chip linear regulator.
With N/Elow, the linear regulator behaves as a 0.7Ω(at
5V output) PFET switch when the IC is boosting, and as
a conventional linear regulator when VIN > VOUT. This
provides optimum boost efficiency, but the PFET does
little to reject boost-converter output ripple. With N/E
high, boost ripple rejection is optimized by maintaining
headroom (VFV, typically 0.5V at 5V output) across the
linear regulator. Boost mode efficiency is then about
10% lower than with N/Ehigh.
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
______________________________________________________________Pin Description
Drain Connection for internal N-channel power MOSFETLX1
Power GroundPGND2
Shutdown Input. When low, the entire circuit is off and OUT is actively pulled to GND.
SHDN
4
Inductor Current-Limit-Select Input. Connect to GND for 1.5A limit and to PS for 0.8A limit.ILIM3
Standby Input. Connect to GND to disable boost circuit. Connect to PS for normal operation.
STBY
5
Selects low-noise or high-efficiency mode. Connect to GND for high efficiency and to PS for
lowest noise. See
Operating Configurations
section.
N/E
7
Selects the output voltage. Connect to GND for 5V output and to OUT for 3.3V output.
3/5
6
2
4
3
5
7
—
1
Low-Battery Comparator OutputLBO8 8
Negative Input to Low-Battery ComparatorLBI-10
Source of internal PFET regulator. The IC is powered from PS.PS12
Positive Input to Low-Battery ComparatorLBI+11
1.28V Reference Voltage Output. Bypass with a 0.1µF capacitor to GND.REF13
Power GroundPGND15
Analog Ground. Must be low impedance. Solder directly to ground plane.GND14
10
12
11
13
15
14
9
Drain Connection for internal N-channel power MOSFETLX16 16
Linear-Regulator Output. Bypass with a 4.7µF capacitor to GND.OUT9
MAX711MAX710 FUNCTIONNAME
PIN
Feedback InputFB— 6
6
Maxim Integrated
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
∆tON
FIXED tOFF
GENERATOR DRV
PS
N/E
PS
OFF
REF2
REF1
CURRENT-
LIMIT COMPARATOR
100mV
VOUT ERROR
AMP2
ERROR
AMP1
REF1
VFV
LX
ILIM
VIN
PGND
PGND
PS
OUT
(FB)
3.3/5
GND
REFB
N
REFA
LBI-
LBI+
STBY
REF
SHDN
LBO
( ) IS FOR MAX711.
REF2
REF1
MAX710
Figure 1. Functional Diagram
MAX710/MAX711
Maxim Integrated
7
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
MAX710
SHDN LX
STBY
N/E
LBO
LBI+
LBI-
REF
PGND
0.1µFGND ILIM
PS
OUT
4.7µF
100µF
VIN = +1.8V TO +11V
100µF
L1
3/5
MAX710
SHDN LX
STBY
N/E
LBO
R5 = R6 (VIN - VREF)
VREF
R5 = R6 (4.08)
WHEN VREF = 1.28V
AND VIN = 6.5V
LBI+
LBI-
REF
PGND
0.1µFGND ILIM
PS
OUT
R6
R5 4.7µF
100µF
VIN = +1.8V TO +11V
100µF
L1
3/5
Figure 2a. High-Efficiency Operating Configuration for
VBATT < VOUT Figure 2b. High-Efficiency Operating Configuration for
VBATT < 6.5V
In high-efficiency mode (N/E= low), the maximum
input voltage is limited to 7V. This voltage limitation is
easily overcome, however, by configuring the LBO out-
put to change modes based on input voltage, allowing
an 11V maximum input with high-efficiency configura-
tions. Four operating configurations are described in
Table 1 and in the following subsections.
Configuration 1: High Efficiency, 7V Max VIN
With N/Econnected to GND, when the IC boosts, the
linear regulator operates only as a switch, with mini-
mum forward drop, until VIN > VOUT (where linear regu-
lation begins). This configuration is limited to no more
than 7V input, but provides best efficiency for battery-
only operation or low-voltage AC adapter usage.
Configuration 2: High Efficiency, VBATT < VOUT
In this configuration, N/Eis driven high by LBO when
VIN > VOUT (Figure 2a). When VIN < VOUT, the IC
boosts, and the linear regulator operates as a switch,
with minimum forward drop. When VIN > VOUT, the lin-
ear regulator operates with VFV forward drop, while VPS
increases by VFV so that OUT maintains regulation. VFV
is set inside the IC to approximately 0.5V (at 5V VOUT).
When VIN is only slightly higher than VOUT, conversion
efficiency is poorer than in configuration 1, so configu-
ration 2 is most suitable when the battery voltage is less
than VOUT, but the AC adapter output is greater than
VOUT.
Up to 11V2
Up to 11V4
Up to 11V3
High efficiency,
VBATT < VOUT
(Figure 2a)
Low noise
High efficiency,
11V, VBATT < 6.5V
(Figure 2b)
DESCRIPTION
High efficiency,
7V max VIN
INPUT
VOLTAGE
Up to 7V1
NO.
LBO = N/E
LBI- = VOUT
LBI+ = VIN
N/E= PS
LBO = N/E
LBI- = REF
LBI+ = R5, R6
CONNECTIONS
N/E= GND
Table 1. Operating Configurations
8
Maxim Integrated
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
Configuration 3: High Efficiency, 11V, VBATT < 6.5V
In this configuration, N/Eis driven high by LBO when
VIN > 6.5V (Figure 2b). When VIN < VOUT, the IC
boosts, and the linear regulator operates as a switch,
with minimum forward drop. When VIN > VOUT, linear
regulation begins. When VIN > 6.5V (set by R5 and R6),
the linear regulator forces a minimum forward drop of
VFV (typically 0.5V at 5V VOUT) as LBO drives N/E high.
This transition is not seen at the output, since the linear
regulator already has an input-output voltage difference
of 6.5V - 5V. Efficiency with VIN slightly higher than
VOUT is equal to that of configuration 1, so configura-
tion 3 is most suitable when the battery voltage may be
near VOUT. This hookup has no functional shortcomings
compared with configuration 2, except that two addi-
tional resistors (R5 and R6) are needed.
Configuration 4: Low Noise
With N/Econnected to PS, when the IC is boosting, the
linear regulator operates with VFV forward voltage (typi-
cally 0.5V at 5V VOUT) for optimum noise rejection.
Linear regulation occurs when VIN > VOUT + VFV. The
VFV voltage differential results in boost efficiency typi-
cally 10% lower than with the high-efficiency configura-
tions.
ILIM
The current-limit-select input, ILIM, selects between the
two peak current limits: 1.5A (ILIM = GND) and 0.8A
(ILIM = PS). If the application requires 200mA or less
from the MAX710/MAX711, select 0.8A. The lower peak
current limit permits the use of smaller, low-cost induc-
tors. The ILIM input is internally diode clamped to GND
and PS, and should not be connected to signals out-
side this range.
Shutdown and Standby Modes
Grounding SHDN turns off the MAX710/MAX711 com-
pletely, disconnecting the input from the output. Tie
SHDN to PS for normal operation.
The MAX710/MAX711 have a standby mode that shuts
down the step-up converter. The linear regulator
remains on with a 7µA (typ) LDO quiescent current.
Connect STBY to ground to enter standby mode; other-
wise, connect STBY to PS.
__________________Design Procedure
Output Voltage Selection
For the MAX710, you can obtain a 3.3V or 5V output
voltage by tying 3/5to GND or PS. Efficiency is typically
85% over a 2mA to 250mA load range. The device is
bootstrapped, with power derived from the step-up
voltage output (at PS). Under all load conditions, the
MAX710/MAX711 typically start up with a 1V input. If
the battery voltage exceeds the programmed output
voltage, the output will linear regulate down to the
selected output voltage.
The MAX711’s adjustable output voltage is set by two
resistors, R1 and R2 (Figure 3), which form a voltage
divider between the output and FB. Use the following
equation to determine the resistor values:
R1 = R2 [(VOUT / VREF) - 1]
where VREF = 1.25V.
Since the input bias current at FB has a maximum value
of 50nA, R1 and R2 can be large with no significant
accuracy loss. Choose R2 in the 100kΩto 1MΩrange
and calculate R1 using the formula above. For 1%
error, the current through R1 should be at least 100
times FB’s bias current.
Low-Battery Comparator
The MAX710/MAX711 contain a comparator for low-
battery detection. If the voltage at LBI+ falls below that
at LBI- (typically connected to REF), LBO goes low.
Hysteresis is typically 50mV. Set the low-battery moni-
tor’s threshold with two resistors, R3 and R4 (Figure 2),
using the following equation:
R3 = R4 [(VLBT / VLBI-) - 1]
MAX711
SHDN LX
STBY
N/E
LBO
LBI+
LBI-
REF
PGND GND ILIM
PS
OUT
R4
R3
R2
R1 C4
C1
IN
C2
L1
FB
OFF
ON
Figure 3. MAX711 Adjustable Output Voltage
MAX710/MAX711
Maxim Integrated
9
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
where VLBT is the desired threshold of the low-battery
detector and VLBI- is the voltage applied to the invert-
ing input of the low-battery comparator. Since LBI cur-
rent is less than 50nA, R3 and R4 can be large
(typically 100kΩto 1MΩ), minimizing input supply load-
ing. If the low-battery comparator is not used, connect
LBI+ to PS and LBI- to REF, leaving LBO unconnected.
Inductor Selection
A 22µH inductor value performs well in most
MAX710/MAX711 applications. The inductance value is
not critical, however, since the MAX710/MAX711 work
with inductors in the 18µH to 100µH range. Smaller
inductance values typically offer a smaller size for a
given series resistance, allowing the smallest overall
circuit dimensions. Circuits using larger inductance val-
ues exhibit higher output current capability and larger
physical dimensions for a given series resistance. The
inductor’s incremental saturation current rating should
be greater than the peak switch-current limit, which is
1.5A for ILIM = GND and 0.8A for ILIM = PS. However,
it is generally acceptable to bias most inductors into
saturation by as much as 20%, although this slightly
reduces efficiency. The inductor’s DC resistance signif-
icantly affects efficiency. See Tables 2 and 3 for a list of
suggested inductors and suppliers.
Capacitor Selection
A 100µF, 16V, 0.1Ωequivalent series resistance (ESR),
surface-mount tantalum (SMT) output filter capacitor,
C2, typically exhibits 50mV output ripple when stepping
up from 2V to 5V at 100mA. Smaller capacitors (down
to 10µF with higher ESRs) are acceptable for light loads
or in applications that can tolerate higher output ripple.
The ESR of both bypass and filter capacitors affects
efficiency and output ripple. Output voltage ripple is the
product of the peak inductor current and the output
capacitor’s ESR. Use low-ESR capacitors for best per-
formance, or connect two or more filter capacitors in
parallel. Low-ESR, SMT capacitors are currently avail-
able from Sprague (595D series) and AVX (TPS series).
Sanyo OS-CON organic-semiconductor through-hole
capacitors also exhibit very low ESR and are especially
useful for operation at cold temperatures. The output
capacitor, C3, needs to be only 4.7µF to maintain linear
regulator stability. See Tables 2 and 3 for a list of sug-
gested capacitors and suppliers.
Rectifier Diode
For optimum performance, use a switching Schottky
diode. Refer to Tables 2 and 3 for the suggested diode
and supplier.
__________Applications Information
The MAX710/MAX711 high-frequency operation makes
PC layout important for minimizing ground bounce and
noise. Keep the IC’s GND pin and the ground leads of
C1 and C2 (Figure 1) less than 0.2in. (5mm) apart. Also
keep all connections to the FB and LX pins as short as
possible. To maximize output power and efficiency and
minimize output ripple voltage, use a ground plane and
solder the IC’s GND pin directly to the ground plane.
4.7µF, 16V tantalum capacitor
Sprague 595D475X0016A2T
RECTIFIERS (D1)
Schottky diode
Motorola MBRS130T3
Coilcraft DO33-08P-223
INDUCTORS (L1)
Sumida CD75-220 (1.5A),
CDRH-74-220 (1.23A), or
CD54-220
CAPACITORS
100µF, 16V low-ESR tantalum capacitor
AVX TPSE107M016R0100 or
Sprague 593D107X0016E2W
Table 2. Component Selection
Table 3. Component Suppliers
(803) 626-3123(803) 946-0690
FAX
AVX
SUPPLIER PHONE
(847) 639-1469(847) 639-6400Coilcraft
(602) 994-6430(602) 303-5454
(603) 224-1430(603) 224-1961Sprague
Motorola
(847) 956-0702(847) 956-0666Sumida
___________________Chip Information
TRANSISTOR COUNT: 661
SUBSTRATE CONNECTED TO GND
(619) 661-1055(619) 661-6835Sanyo
10
Maxim Integrated
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
________________________________________________________Package Information
SOICN.EPS
MAX710/MAX711
Maxim Integrated
11
3.3V/5V or Adjustable,
Step-Up/Down DC-DC Converters
NOTES
12 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
© 1997 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.