19-3357; Rev 0; 8/04
Dual-Phase MOSFET Drivers
with Temperature Sensor
General Description
The MAX8702/MAX8703 dual-phase noninverting
MOSFET drivers are designed to work with PWM con-
troller ICs, such as the MAX8705/MAX8707, in note-
book CPU core and other multiphase regulators.
Applications can either step down directly from the bat-
tery voltage to create the core voltage, or step down
from a low-voltage system supply. The single-stage con-
version method allows the highest possible efficiency,
while the 2-stage conversion at higher switching frequen-
cy provides the minimum possible physical size.
Each MOSFET driver is capable of driving 3nF capaci-
tive loads with only 19ns propagation delay and 8ns
typical rise and fall times. Larger capacitive loads are
allowable but result in longer propagation and transition
times. Adaptive dead-time control helps prevent shoot-
through currents and maximizes converter efficiency.
The MAX8702/MAX8703 feature zero-crossing com-
parators on each channel. When enabled, these com-
parators permit the drivers to be used in pulse-skipping
operation, thereby saving power at light loads. A sepa-
rate shutdown control is also included that disables all
functions, drops quiescent current to 2µA, and sets DH
low and DL high.
The MAX8702 integrates a resistor-programmable tem-
perature sensor. An open-drain output (DRHOT) signals
to the system when the local die temperature exceeds
the set temperature. The MAX8702/MAX8703 are avail-
able in a thermally-enhanced 20-pin thin QFN package.
Features
o
Dual-Phase MOSFET Driver
o
0.35Ω (typ) On-Resistance and 5A (typ)
Drive Current
o
Drives Large Synchronous-Rectifier MOSFETs
o
Integrated Temperature Sensor (MAX8702 Only)
Resistor Programmable
Open-Drain Driver Hot Indicator (DRHOT)
o
Adaptive Dead Time Prevents Shoot-Through
o
Selectable Pulse-Skipping Mode
o
4.5V to 28V Input Voltage Range
o
Thermally Enhanced Low-Profile Thin QFN Package
MAX8702/MAX8703
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
DESCRIPTION
Dual-Phase
20 Thin QFN
Driver with
MAX8702ETP
-40°C to +100°C
4mm x 4mm
Temp. Sensor
Dual-Phase
20 Thin QFN
Driver without
MAX8703ETP
-40°C to +100°C
4mm x 4mm
Temp. Sensor
Minimal Operating Circuit
+5V
V
DD
V
IN
4.5V TO 28V
Applications
Multiphase High-Current Power Supplies
2- to 4-Cell Li+ Battery to CPU Core Supplies
Notebook and Desktop Computers
Servers and Workstations
+5V
BST1
DH1
V
CC
AGND
LX1
DL1
PGND1
V
OUT
TSET
+5V
MAX8702
BST2
DRHOT
SHDN
LX2
SKIP
PWM1
PWM2
DL2
PGND2
DH2
V
OUT
V
IN
4.5V TO 28V
Pin Configuration appears at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Dual-Phase MOSFET Drivers
with Temperature Sensor
MAX8702/MAX8703
ABSOLUTE MAXIMUM RATINGS
V
CC
to AGND............................................................-0.3V to +6V
V
DD
to AGND............................................................-0.3V to +6V
PGND_ to AGND ...................................................-0.3V to +0.3V
SKIP, SHDN, DRHOT,
TSET to AGND......................-0.3V to +6V
PWM_ to AGND ........................................................-0.3V to +6V
DL_ to PGND_ ............................................-0.3V to (V
DD
+ 0.3V)
LX_ to AGND .............................................................-2V to +30V
DH_ to LX_ ...............................................-0.3V to (V
BST_
+ 0.3V)
BST_ to LX_ ..............................................................-0.3V to +6V
Continuous Power Dissipation (T
A
= +70°C)
20-Pin 4mm x 4mm Thin QFN
(derate 16.9mW/°C
above +70°C) .............................1349mW
Operating Temperature Range .........................-40°C to +100°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(Circuit of
Figure
2. V
CC
= V
DD
= V
SHDN
= V
SKIP
= 5V,
T
A
= 0°C to +85°C.
Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
Input Voltage Range
V
CC
Undervoltage-Lockout
Threshold
V
CC
Quiescent Current
(Note 1)
V
DD
Quiescent Current
V
CC
Shutdown Current
V
DD
Shutdown Current
t
PWM-DL
t
DH-DL
t
DL-DH
t
PWM-DH
t
F
_
DL
t
R
_
DL
t
F
_
DH
t
R
_
DH
R
DH
R
DL
_
HIGH
R
DL
_
LOW
I
DH
SYMBOL
V
CC
V
UVLO
I
CC
I
DD
85mV typical
hysteresis
V
CC
rising
V
CC
falling
CONDITIONS
MIN
4.5
3.4
3.3
3.85
3.75
200
2
1
2
1
19
36
25
23
11
8
14
16
1.0
1.0
0.35
1.5
1.5
5
2.5
4.5
4.5
2.0
TYP
MAX
5.5
4.1
4.0
400
3
5
5
5
UNITS
V
V
µA
mA
µA
µA
µA
SKIP
= AGND, PWM_ = AGND
SKIP
= AGND, PWM_ = V
CC
SKIP
= AGND, PWM_ = AGND
SHDN
=
SKIP
= AGND
SHDN
=
SKIP
= AGND
PWM_ high to DL_ low
DH_ low to DL_ high
DL_ low to DH_ high
PWM_ low to DH_ low
DL_ falling, 3nF load
DL_ rising, 3nF load
DH_ falling, 3nF load
DH_ rising, 3nF load
V
BST
_ - V
LX
_ = 5V
High state (pullup)
Low state (pulldown)
V
DH
_ = 2.5V, V
BST
_ - V
LX
_ = 5V
GATE DRIVERS AND DEAD-TIME CONTROL (Figure 1)
DL_ Propagation Delay
DH_ Propagation Delay
DL_ Transition Time
DH_ Transition Time
DH_ On-Resistance (Note 2)
DL_ On-Resistance (Note 2)
DH_ Source/Sink Current
DL_ Source Current
DL_ Sink Current
Zero-Crossing Threshold
TEMPERATURE SENSOR
Temperature Threshold
Accuracy
DRHOT
Output Low Voltage
DRHOT
Leakage Current
T
A
= +85°C to +125°C, 10°C falling hysteresis
I
SINK
= 3mA
High state, V
DRHOT
= 5.5V
-5
+5
0.4
1
°C
V
µA
ns
ns
ns
ns
Ω
Ω
A
A
A
mV
I
DL
_
SOURCE
V
DL
_ = 2.5V
I
DL
_
SINK
V
DL
_ = 5V
V
PGND
_ - V
LX
_,
SKIP
= AGND
2
_______________________________________________________________________________________
Dual-Phase MOSFET Drivers
with Temperature Sensor
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of
Figure
2. V
CC
= V
DD
= V
SHDN
= V
SKIP
= 5V,
T
A
= 0°C to +85°C.
Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
Thermal-Shutdown Threshold
LOGIC CONTROL SIGNALS
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
SHDN, SKIP,
PWM1, PWM2
SHDN, SKIP,
PWM1, PWM2
SHDN, SKIP,
PWM1, PWM2
-1
2.4
0.8
+1
V
V
µA
SYMBOL
10°C hysteresis
CONDITIONS
MIN
TYP
+160
MAX
UNITS
°C
MAX8702/MAX8703
ELECTRICAL CHARACTERISTICS
(Circuit of
Figure
2. V
CC
= V
DD
= V
SHDN
= V
SKIP
= 5V,
T
A
= -40°C to +100°C,
unless otherwise noted.) (Note 3)
PARAMETER
Input Voltage Range
V
CC
Undervoltage-Lockout
Threshold
V
CC
Quiescent Current
V
DD
Quiescent Current
V
CC
Shutdown Current
V
DD
Shutdown Current
GATE DRIVERS AND DEAD-TIME CONTROL
DH_ On-Resistance (Note 2)
DL_ On-Resistance (Note 2)
TEMPERATURE SENSOR
DRHOT
Output Low Voltage
LOGIC CONTROL SIGNALS
Logic Input High Voltage
Logic Input Low Voltage
SHDN, SKIP,
PWM1, PWM2
SHDN, SKIP,
PWM1, PWM2
2.4
0.8
V
V
I
SINK
= 3mA
0.4
V
R
DH
R
DL
_
HIGH
R
DL
_
LOW
V
BST
_ - V
LX
_ = 5V
High state (pullup)
Low state (pulldown)
1.0
1.0
0.35
4.5
4.5
2.0
Ω
Ω
SYMBOL
V
CC
V
UVLO
I
CC
I
DD
85mV typical
hysteresis
V
CC
rising
V
CC
falling
CONDITIONS
MIN
4.5
3.4
3.3
TYP
MAX
5.5
4.1
4.0
450
3
5
5
5
UNITS
V
V
µA
mA
µA
µA
µA
SKIP
= AGND, PWM_ = PGND_
SKIP
= AGND, PWM_ = V
CC
SKIP
= AGND, PWM_ = PGND_,
T
A
= -40°C to +85°C
SHDN
=
SKIP
= AGND, T
A
= -40°C to +85°C
SHDN
=
SKIP
= AGND, T
A
= -40°C to +85°C
Note 1:
Static drivers instead of pulsed-level translators.
Note 2:
Production testing limitations due to package handling require relaxed maximum on-resistance specifications for the
thin QFN package.
Note 3:
Specifications from -40°C to +100°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
3
Dual-Phase MOSFET Drivers
with Temperature Sensor
MAX8702/MAX8703
PWM_
90%
90%
DH_
DL_
t
PWM-DL
t
F_DL
90%
10%
t
DL-DH
t
R_DH
t
PWM-DH
t
F_DH
10%
t
DH-DL
t
R_DL
90%
10%
10%
Figure 1. Timing Definitions Used in the Electrical Characteristics
Typical Operating Characteristics
(Circuit of
Figure
2. V
IN
= 12V, V
DD
= V
CC
= V
SHDN
= V
SKIP
= 5V, T
A
= +25°C unless otherwise noted.)
POWER DISSIPATION vs. FREQUENCY
(SINGLE PHASE, BOTH DRIVERS SWITCHING)
MAX8702/03 toc01
POWER DISSIPATION vs. CAPACITIVE LOAD
(SINGLE PHASE, BOTH DRIVERS SWITCHING)
FREQ = 1.2MHz
POWER DISSIPATION (mW)
300
FREQ = 0.6MHz
200
MAX8702/03 toc02
350
300
POWER DISSIPATION (mW)
250
200
150
100
50
0
0
0.2
0.4
0.6
0.8
FREQUENCY (MHz)
C
DL
= 3nF,
C
DH
= 1.5nF
V
CC
= 5.5V
C
DL
= 3nF, C
DH
= 3nF
C
DL
= 6nF, C
DH
= 3nF
400
100
FREQ = 0.3MHz
0
1
2
3
4
V
CC
= 5.5V,
C
DH
= C
DL
5
6
1.0
1.2
CAPACITANCE (nF)
DL RISE/FALL TIME vs. CAPACITIVE LOAD
MAX8702/03 toc03
DH RISE/FALL TIME vs. CAPACITIVE LOAD
MAX8702/03 toc04
20
30
25
RISE/FALL TIME (ns)
DH RISE
20
15
DH FALL
10
5
RISE/FALL TIME (ns)
15
DL RISE
10
DL FALL
5
0
1
2
3
4
5
6
CAPACITANCE (nF)
0
1
2
3
4
5
6
CAPACITANCE (nF)
4
_______________________________________________________________________________________
Dual-Phase MOSFET Drivers
with Temperature Sensor
MAX8702/MAX8703
Typical Operating Characteristics (continued)
(Circuit of
Figure
2. V
IN
= 12V, V
DD
= V
CC
= V
SHDN
= V
SKIP
= 5V, T
A
= +25°C unless otherwise noted.)
DH/DL RISE/FALL TIMES
vs. TEMPERATURE
DH RISE
DH FALL
MAX8702 toc05
PROPAGATION DELAY vs. TEMPERATURE
DL FALL TO DH RISE
PROPAGATION DELAY (ns)
40
PWM FALL TO DH FALL
30
MAX8702 toc06
20
50
RISE/FALL TIME (ns)
15
10
DL RISE
5
DL FALL
C
DH
= C
DL
= 3nF
0
0
20
40
60
80
100
120
TEMPERATURE (°C)
20
PWM RISE TO DL FALL
10
C
DH
= C
DL
= 3nF
0
0
30
60
90
120
150
TEMPERATURE (°C)
R
TSET
vs. TEMPERATURE
MAX8702 toc07
TYPICAL SWITCHING WAVEFORMS
MAX8702 toc08
70
60
50
R
TSET
(kΩ)
5V
A
0
5V
B
0
10V
0
0
125ns/div
C. DH, 10V/div
D. LX, 10V/div
C
D
40
30
20
10
0
50
70
90
110
130
150
A. PWM, 5V/div
B. DL, 5V/div
TEMPERATURE (°C)
DH RISE AND DL FALL WAVEFORMS
MAX8702 toc09
DH FALL AND DL RISE WAVEFORMS
MAX8702 toc10
5V
A
0
5V
B
0
10V
0
D
0
20ns/div
C. DH, 10V/div
D. LX, 10V/div
C
5V
A
0
5V
0
10V
0
0
20ns/div
C. DH, 10V/div
D. LX, 10V/div
D
B
C
A. PWM, 5V/div
B. DL, 5V/div
A. PWM, 5V/div
B. DL, 5V/div
_______________________________________________________________________________________
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