19-3569; Rev 2; 4/07
KIT
ATION
EVALU
BLE
AVAILA
Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
General Description
The MAX8716/MAX8717/MAX8756/MAX8757 are dual,
step-down, interleaved, fixed-frequency, switch-mode
power-supply (SMPS) controllers with synchronous rec-
tification. The MAX8716/MAX8717/MAX8756/MAX8757
are intended for main (5V/3.3V) power generation, while
the MAX8756 is optimized for I/O power rails in battery-
powered systems.
Fixed-frequency operation with optimal interleaving min-
imizes input ripple current from the lowest input voltages
up to the 26V maximum input. Optimal 40/60 interleav-
ing allows the input voltage to go down to 8.3V before
duty-cycle overlap occurs in 5V/3.3V applications, com-
pared to 180° out-of-phase regulators where the duty-
cycle overlap occurs when the input drops below 10V.
Accurate output current limit is achieved using a sense
resistor. Alternatively, power dissipation can be
reduced using lossless inductor current sensing.
Independent ON/OFF controls and power-good signals
allow flexible power sequencing. Soft-start reduces
inrush current, while soft-stop gradually ramps the out-
put voltage down preventing negative voltage dips.
A low-noise mode maintains high light-load efficiency
while keeping the switching frequency out of the audi-
ble range.
The MAX8716 is available in a 24-pin thin QFN pack-
age, and the MAX8717/MAX8756/MAX8757 are avail-
able in a 28-pin thin QFN package.
Features
o
Fixed Switching Frequency
200kHz, 300kHz, or 500kHz
250kHz, 300kHz, or 400kHz (MAX8756 Only)
o
No Current-Sense Resistor Required
o
40/60 Optimal Interleaving
o
Reduced Input-Capacitor Requirement
o
Output Voltage Fixed or Adjustable Outputs
(Dual Mode™)
3.3V/5V Fixed or 1V to 5.5V Adjustable
1.5V/1.8V Fixed or 1V to 2.3V Adjustable
(MAX8756 Only)
o
4V to 26V Input Range
o
Independently Selectable PWM, Skip, and Low-
Noise Mode Operation
o
Soft-Start and Soft-Stop
o
2V Precision Reference with 0.75% Accuracy
o
Independent Power-Good Outputs
MAX8716/MAX8717/MAX8756/MAX8757
Ordering Information
PART
MAX8716ETG
MAX8716ETG+
MAX8717ETI
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
24 Thin QFN
4mm x 4mm
24 Thin QFN
4mm x 4mm
28 Thin QFN
5mm x 5mm
PKG
CODE
T2444-4
T2444-4
T2855-6
Applications
2 to 4 Li+ Cell Battery-Powered Devices
Notebook and Subnotebook Computers
PDAs and Mobile Communicators
Main or I/O Power Supplies
Dual Mode is a trademark of Maxim Integrated Products, Inc.
+Denotes
a lead-free package.
Ordering Information continued at end of data sheet.
Pin Configurations
AGND
GND
PGND
TOP VIEW
DL1
DL2
V
DD
LX1
LX2
TOP VIEW
DL1
LX1
DL2
16
V
DD
18
DH1
17
16
15
14
13
DH1
21
22
23
24
25
26
27
28
+
20
19
18
17
15
14
13
12
DH2
19
20
21
22
23
24
+
12
11
10
DH2
BST1
CSH1
CSL1
BST2
CSH2
CSL2
BST1
CSH1
CSL1
FB1
PGOOD1
ILIM1
LX2
BST2
CSH2
CSL2
FB2
PGOOD2
ILIM2
MAX8716ETG
9
8
7
FB1
PGOOD1
FB2
PGOOD2
MAX8717ETI
MAX8756ETI+
MAX8757ETI+
11
10
9
8
1
2
3
4
5
6
V
CC
SKIP1
REF
SKIP2
ON1
ON2
1
2
3
4
5
6
ON1
7
ON2
V
CC
SKIP1
REF
SKIP2
TQFN
A "+" SIGN WILL REPLACE THE FIRST PIN INDICATOR ON LEAD-FREE PACKAGES.
TQFN
________________________________________________________________
Maxim Integrated Products
FSEL
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.
Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
MAX8716/MAX8717/MAX8756/MAX8757
ABSOLUTE MAXIMUM RATINGS (Note 1)
V
DD
, V
CC
, CSL1, CSH1, CSL2, CSH2 to AGND ......-0.3V to +6V
ON1, ON2,
SKIP1, SKIP2,
PGOOD1,
PGOOD2 to AGND ...............................................-0.3V to +6V
FB1, FB2, ILIM1, ILIM2, FSEL to AGND ...................-0.3V to +6V
REF to AGND..............................................-0.3V to (V
CC
+ 0.3V)
BST1, BST2 to AGND .............................................-0.3V to +36V
LX1 to BST1..............................................................-6V to +0.3V
LX2 to BST2..............................................................-6V to +0.3V
DH1 to LX1 ..............................................-0.3V to (V
BST1
+ 0.3V)
DH2 to LX2 ..............................................-0.3V to (V
BST2
+ 0.3V)
DL1, DL2 to PGND .....................................-0.3V to (V
DD
+ 0.3V)
AGND to PGND .....................................................-0.3V to +0.3V
REF Short Circuit to AGND.........................................Continuous
REF Current ......................................................................+10mA
Continuous Power Dissipation (T
A
= +70°C)
24-Pin Thin QFN 4mm x 4mm (derate 20.8mW/°C
above +70°C)..........................................................1666.7mW
28-Pin Thin QFN 5mm x 5mm (derate 21.3mW/°C
above +70°C)..........................................................1702.1mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
For the 24-pin TQFN version, AGND and PGND refer to a single pin designated GND.
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 1, V
IN
= 12V, FSEL = REF,
SKIP_
= 0, V
ON_
= V
ILIM_
= V
CC
= V
DD
= 5V
,
T
A
= 0°C to +85°C,
unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
INPUT SUPPLIES
Input Voltage Range
V
CC
Undervoltage-Lockout
Threshold
Quiescent Supply Current (V
CC
)
Quiescent Supply Current (V
DD
)
Shutdown Supply Current (V
CC
)
Shutdown Supply Current (V
DD
)
MAIN SMPS CONTROLLERS
PWM1 Output Voltage in
Fixed Mode
PWM2 Output Voltage in
Fixed Mode
V
OUT1
V
IN
= 6V to 26V,
SKIP1
= V
CC
,
zero to full load
V
IN
= 6V to 26V,
SKIP2
= V
CC
,
zero to full load
MAX8716, MAX8717,
MAX8757
MAX8756
MAX8716, MAX8717,
MAX8757
MAX8756
3.265
1.484
4.94
1.778
0.990
0.995
1.0
1.0
3.30
1.50
5.00
1.800
1.005
1.005
3.365
1.530
5.09
1.832
1.020
V
1.015
5.5
2.3
V
V
V
IN
V
BIAS
V
UVLO
V
CC
, V
DD
200mV typical
hysteresis
CSL_ and FB_ forced
above their regulation
points
V
CC
rising
V
CC
falling
MAX8716, MAX8717,
MAX8757
MAX8756
4.5
3.9
3.7
4.15
3.95
0.8
1
<1
<1
<1
26
5.5
4.4
4.2
1.3
1.8
5
5
5
µA
µA
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
I
CC
I
DD
mA
CSL_ and FB_ forced above their regulation
points
ON1 = ON2 = GND
ON1 = ON2 = GND
V
OUT2
Feedback Voltage in Adjustable
Mode (Note 2)
V
FB_
Output-Voltage-Adjust Range
V
IN
= 6V to 26V, FB1 or FB2,
duty factor = 20% to 80%
V
IN
= 6V to 26V, FB1 or FB2,
duty factor = 50%
MAX8716, MAX8717,
MAX8757
Either SMPS
MAX8756
V
2
_______________________________________________________________________________________
Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= 12V, FSEL = REF,
SKIP_
= 0, V
ON_
= V
ILIM_
= V
CC
= V
DD
= 5V
,
T
A
= 0°C to +85°C,
unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
FB1, FB2 Fixed-Mode Threshold
Voltage
Feedback Input Leakage Current
DC Load Regulation
Line-Regulation Error
FB_ Input Bias Current
I
FB_
SYMBOL
CONDITIONS
Dual Mode comparator
FB1 = 1.1V, FB2 = 1.1V
Either SMPS,
SKIP_
= V
CC
, zero to full load
Either SMPS, 4V < V
IN
< 26V
V
FB_
= 0 to 5.5V
FSEL = GND
Operating Frequency
f
OSC
FSEL = REF (Note 3)
FSEL = V
CC
FSEL = GND
Maximum Duty Factor
Minimum On-Time
SMPS1 to SMPS2 Phase Shift
Soft-Start Ramp Time
Soft-Stop Ramp Time
CURRENT LIMIT
ILIM_ Adjustment Range
Current-Limit Threshold (Fixed)
Current-Limit Threshold
(Adjustable)
V
LIMIT
_
V
LIMIT
_
V
CSH
_ - V
CSL
_, ILIM_ = V
CC
(Note 3)
V
CSH
_ - V
CSL
_
V
ILIM
_ = 2.00V
V
ILIM
_ = 1.00V
0.5
45
190
94
-67
50
200
100
-60
-120
3
6
10
20
14
V
REF
55
210
106
-53
V
mV
mV
mV
%
mV
mV
%
t
SSTART
t
SSTOP
D
MAX
t
ON(MIN)
FSEL = REF (Note 3)
FSEL = V
CC
(Note 4)
SMPS2 starts after SMPS1
Measured from the rising edge of ON_ to full
scale, REF = 2V
Measured from the falling edge of ON_ to full
scale
40
144
2
4
MAX8716, MAX8717,
MAX8757
MAX8756
MAX8716, MAX8717,
MAX8757
MAX8756
-0.1
170
215
270
425
340
97.5
97.5
97.5
200
250
300
500
400
99
99
99
200
ns
%
Degrees
ms
ms
%
MIN
1.9
-0.1
-0.1
0.03
+0.1
230
285
330
575
460
kHz
TYP
MAX
2.1
+0.1
UNITS
V
µA
%
%/V
µA
MAX8716/MAX8717/MAX8756/MAX8757
Current-Limit Threshold
(Negative)
V
CSH
_ - V
CSL
_,
SKIP_
= ILIM_ = V
CC
(Note 3)
V
NEG
V
CSH
_ - V
CSL
_,
SKIP_
= V
CC
, adjustable
mode, percent of current limit
V
CSH
_ - V
CSL
_,
SKIP_
= GND or REF
ILIM_ = V
CC
(Note 3)
Current-Limit Threshold
(Zero Crossing)
V
ZX
Idle Mode™ Threshold
V
IDLE
V
CSH
_ - V
CSL
_,
SKIP_
= GND
With respect to
current-limit
threshold
Idle Mode is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________________________________
3
Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
MAX8716/MAX8717/MAX8756/MAX8757
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= 12V, FSEL = REF,
SKIP_
= 0, V
ON_
= V
ILIM_
= V
CC
= V
DD
= 5V
,
T
A
= 0°C to +85°C,
unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MAX8716, MAX8717,
V
CSH
_ - V
CSL
_
MAX8757
SKIP_
= REF
ILIM_ = V
CC
(Note 3) MAX8756
Low-Noise-Mode Threshold
V
IDLE
V
CSH
_ - V
CSL
_
SKIP_
= REF with
respect to current-
limit threshold
I
REF
= 0µA to 50µA
10
V
REF(UVLO)
Rising edge, hysteresis = 50mV
1.8
MAX8716, MAX8717,
MAX8757
MAX8756
MIN
2.5
1
TYP
5
2.5
10
%
5
0.1
ΔV
REF
10
µA
mV
µA
V
MAX
7.5
4
UNITS
mV
ILIM_ Leakage Current
Reference Load Regulation
Reference Sink Current
REF Lockout Voltage
FAULT DETECTION
Output Overvoltage Trip
Threshold
Output Overvoltage
Fault-Propagation Delay
Output Undervoltage-Protection
Trip Threshold
Output Undervoltage
Fault-Propagation Delay
Output Undervoltage-Protection
Blanking Time
PGOOD_ Lower Trip Threshold
PGOOD_ Propagation Delay
PGOOD_ Output Low Voltage
PGOOD_ Leakage Current
Thermal-Shutdown Threshold
GATE DRIVERS
DH_ Gate-Driver On-Resistance
DL_ Gate-Driver On-Resistance
(Note 5)
DH_ Gate-Driver Source/Sink
Current
DL_ Gate-Driver Source Current
DL_ Gate-Driver Sink Current
Dead Time
LX_, BST_ Leakage Current
R
DH
R
DL
I
DH
I
DL
(SOURCE)
MAX8716/MAX8717/MAX8756 only
t
OVP
50mV overdrive,
MAX8716/MAX8717/MAX8756 only
With respect to error-comparator threshold
t
UVP
t
BLANK
50mV overdrive
From rising edge of ON_
With respect to error-comparator threshold,
hysteresis = 1%
Falling edge, 50mV overdrive
I
SINK
= 4mA
I
PGOOD
_
T
SHDN
High state, PGOOD_ forced to 5.5V
Hysteresis = 15°C
BST_ - LX_ forced to 5V (Note 5)
DL_, high state
DL_, low state
DH_ forced to 2.5V, BST_ - LX_ forced to
5V
DL_ forced to 2.5V
DL_ forced to 2.5V
DL_ rising
DH_ rising
V
BST
_ = V
LX
_ = 26V
11
15
10
19
%
µs
65
70
10
6144
75
%
µs
1/f
OSC
-12.5
-10
10
-8.0
%
µs
t
PGOOD
_
0.4
1
+160
1.5
1.7
0.6
2
1.7
3.3
35
26
<2
20
5
5
3
V
µA
°C
Ω
Ω
A
A
A
ns
µA
I
DL (SINK)
t
DEAD
4
_______________________________________________________________________________________
Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
MAX8716/MAX8717/MAX8756/MAX8757
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= 12V, FSEL = REF,
SKIP_
= 0, V
ON_
= V
ILIM_
= V
CC
= V
DD
= 5V
,
T
A
= 0°C to +85°C,
unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
INPUTS AND OUTPUTS
Logic Input Current
ON_ Input Voltage
Tri-Level Input Logic
Input Leakage Current
Input Leakage Current
Input Leakage Current
Input Bias Current
ON1, ON2
Rising edge, hysteresis = 225mV
SKIP1, SKIP2,
FSEL, high
SKIP1, SKIP2,
FSEL, 0V, or V
CC
ILIM1, ILIM2, 0V, or V
CC
CSH_, 0V, or V
DD
CSL_, 0V, or V
DD
-1
1.2
V
CC
-
0.2
-3
-0.1
-0.1
25
1.7
+1
2.2
µA
V
V
+3
+0.1
+0.1
50
µA
µA
µA
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V
IN
= 12V, FSEL = REF,
SKIP_
= 0, V
ON_
= V
ILIM_
= V
CC
= V
DD
= 5V,
T
A
= -40°C to +85°C,
unless otherwise
noted.) (Note 6)
PARAMETER
INPUT SUPPLIES
Input Voltage Range
V
IN
V
BIAS
I
CC
V
CC
, V
DD
CSL_ and FB_
forced above their
regulation points
MAX8716, MAX8717,
MAX8757
MAX8756
4.5
26
5.5
1.3
1.8
5
5
5
MAX8716, MAX8717,
MAX8757
MAX8756
MAX8716, MAX8717,
MAX8757
MAX8756
µA
µA
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Quiescent Supply Current (V
CC
)
mA
Quiescent Supply Current (V
DD
)
Shutdown Supply Current (V
CC
)
Shutdown Supply Current (V
DD
)
MAIN SMPS CONTROLLERS
PWM1 Output Voltage in
Fixed Mode
PWM2 Output Voltage in
Fixed Mode
Feedback Voltage in
Adjustable Mode
Output Voltage Adjust Range
FB1, FB2 Fixed-Mode
Threshold Voltage
I
DD
CSL_ and FB_ forced above their regulation
points
ON1 = ON2 = GND
ON1 = ON2 = GND
V
IN
= 6V to 26V,
SKIP1
= V
CC
,
zero to full load
V
IN
= 6V to 26V,
SKIP2
= V
CC
,
zero to full load
V
OUT1
3.255
1.480
4.925
1.773
0.987
1.0
1.0
1.9
3.375
1.534
5.105
1.838
1.023
5.5
2.3
2.1
V
V
OUT2
V
V
FB_
V
IN
= 6V to 26V, FB1 or FB2,
duty factor = 20% to 80% (Note 1)
MAX8716, MAX8717,
MAX8757
Either SMPS
MAX8756
Dual Mode comparator
V
V
V
_______________________________________________________________________________________
5
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