_______________General Description
The MAX783 is a system-engineered power-supply controller
for notebook computers or similar battery-powered equipment.
It provides two high-performance step-down (buck) pulse-
width modulators (PWMs) for +3.3V/+5V and dual PCMCIA
VPP outputs powered by an integral flyback winding controller.
Other functions include dual, low-dropout, micropower linear
regulators for CMOS/RTC back up, and two precision low-
battery-detection comparators.
High efficiency (95% at 2A, greater than 80% at loads from
5mA to 3A) is achieved through synchronous rectification
and PWM operation at heavy loads, and Idle-Mode
TM
oper-
ation at light loads. The MAX783 uses physically small
components, thanks to high operating frequencies
(300kHz/200kHz) and a new current-mode PWM architec-
ture that allows for output filter capacitors as small as 30F
per ampere of load. Line- and load-transient responses
are terrific, with a high 60kHz unity-gain crossover frequen-
cy that allows output transients to be corrected within four
or five clock cycles. Low system cost is achieved through
a high level of integration and the use of low-cost external
N-channel MOSFETs. The integral flyback winding con-
troller provides a low-cost, +15V high-side output that regu-
lates even in the absence of a load on the main output.
Other features include low-noise, fixed-frequency PWM
operation at moderate to heavy loads and a synchronizable
oscillator for noise-sensitive applications such as electro-
magnetic pen-based systems and communicating comput-
ers. The MAX783 is similar to the MAX782, except the fly-
back winding is on the 3.3V inductor instead of the 5V
inductor, the VPP outputs can be optionally programmed to
3.3V, and the device may be completely shut down.
________________________Applications
Notebook Computers
Portable Data Terminals
Communicating Computers
Pen-Entry Systems
____________________________Features
o
Dual PWM Buck Controllers (+3.3V and +5V)
o
Dual PCMCIA VPP Outputs (0V/3.3V/5V/12V)
o
Two Precision Comparators or Level Translators
o
Power-Ready Status Output (
RDY5
)
o
95% Efficiency
o
Optimized for 6-Cell Applications
o
420A Quiescent Current;
70A in Standby (linear regulators alive)
25A Shutdown Current
o
5.5V to 30V Input Range
o
Small SSOP Package
o
Fixed Output Voltages Available:
3.3V (standard)
3.45V (High-Speed PentiumTM)
3.6V (PowerPCTM)
______________Ordering Information
MAX783
Triple-Output Power-Supply Controller
for Notebook Computers
________________________________________________________________
Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
TM
Idle-Mode is a trademark of Maxim Integrated Products. Pentium is a trademark of Intel. PowerPC is a trademark of IBM.
19-0045; Rev 1; 5/94
Evaluation Kit
Information Included
MAX783
5.5V
TO
30V
VPP
CONTROL
ON3
ON5
SYNC
POWER
SECTION
SUSPEND POWER
LOW-BATTERY WARNING
VPP (0V/3.3V/5V/12V)
P
MEMORY
PERIPHERALS
+3.3V
+5V
DUAL
PCMCIA
SLOTS
4
VPP (0V/3.3V/5V/12V)
SHDN
_______Typical Application Diagram
36
35
34
33
32
31
30
29
28
27
26
25
24
23
1
2
3
4
5
6
7
8
9
10
11
12
13
14
SS3
CS3
FB3
DH3
LX3
BST3
LX5
DL3
V+
VL
FB5
PGND
DL5
BST5
SYNC
REF
GND
VPPB
VDD
VPPA
RDY5
Q1
Q2
VH
D2
D1
SHDN
ON3
SSOP
TOP VIEW
MAX783
22
21
20
19
15
16
17
18
ON5
DH5
CS5
SS5
DB0
DB1
DA0
DA1
__________________Pin Configuration
36 SSOP
0C to +70C
MAX783RCBX
36 SSOP
0C to +70C
MAX783CBX
PIN-PACKAGE
TEMP. RANGE
PART
3.45V
3.3V
V
OUT
Ordering Information continued on last page.
MAX783
Triple-Output Power-Supply Controller
for Notebook Computers
2
_______________________________________________________________________________________
V+ to GND .................................................................-0.3V, +36V
PGND to GND........................................................................2V
VL to GND ...................................................................-0.3V, +7V
BST3, BST5 to GND ..................................................-0.3V, +36V
LX3 to BST3.................................................................-7V, +0.3V
LX5 to BST5.................................................................-7V, +0.3V
Inputs/Outputs to GND
(D1, D2, S
--
H
--
D
--
N
, ON5, REF, SYNC, DA1, DA0, DB1, DB0, ON5,
SS5, CS5, FB5, R
--
D
--
Y
--
5
, CS3, FB3, SS3, ON3).-0.3V, (VL + 0.3V)
VDD to GND.................................................................-0.3V, 20V
VPPA, VPPB to GND.....................................-0.3V, (VDD + 0.3V)
VH to GND ...................................................................-0.3V, 20V
Q1, Q2 to GND................................................-0.3V, (VH + 0.3V)
DL3, DL5 to PGND..........................................-0.3V , (VL + 0.3V)
DH3 to LX3 ..................................................-0.3V, (BST3 + 0.3V)
DH5 to LX5 ..................................................-0.3V, (BST5 + 0.3V)
REF, VL, VPP Short to GND........................................Momentary
REF Current.........................................................................20mA
VL Current ...........................................................................50mA
VPPA, VPPB Current .........................................................100mA
Continuous Power Dissipation (T
A
= +70C)
SSOP (derate 11.76mW/C above +70C) ...................762mW
Operating Temperature Ranges:
MAX783CBX/MAX783_CBX.................................0C to +70C
MAX783EBX/MAX783_EBX ..............................-40C to +85C
Storage Temperature Range .............................-65C to +160C
Lead Temperature (soldering, 10sec) .............................+300C
ELECTRICAL CHARACTERISTICS
(V+ = 15V, GND = PGND = 0V, I
VL
= I
REF
= 0mA, S
--
H
--
D
--
N
= ON3 = ON5 = 5V, other digital input levels are 0V or +5V,
T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
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.
ABSOLUTE MAXIMUM RATINGS
VDD = 18V, ON3 = ON5 = 5V, VPPA/VPPB programmed to
0V
0mV < (CS5-FB5) < 70mV, 6V < V + < 30V
(includes load and line regulation)
Program to 0V, 13V < VDD < 19V, 0mA < I
L
< 0.3mA
Program to 3.3V, 13V < VDD < 19V, 0mA < I
L
< 60mA
Program to 5V, 13V < VDD < 19V, 0mA < I
L
< 60mA
Program to 12V, 13V < VDD < 19V, 0mA < I
L
< 60mA
VDD = 18V, ON3 = ON5 = 5V, VPPA/VPPB programmed to
12V with no external load
VDD = 20V
CS3-FB3 (VDD < 13V, flyback mode)
Either controller (0mV to 70mV)
Either controller (6V to 30V)
Rising edge, hysteresis = 1%
CS3-FB3 or CS5-FB5
Falling edge, hysteresis = 1%
CONDITIONS
V
4.80
5.08
5.20
-0.30
0.30
FB5 Output Voltage
3.17
3.30
3.43
V
5.5
30
4.85
5.05
5.20
V
11.60
12.10
12.50
VPPA/VPPB Output Voltage
Input Supply Range
A
15
30
Off VDD Current
A
mA
140
300
2
SS3/SS5 Fault Sink Current
Quiescent VDD Current
mA
2
3
A
2.5
4.0
6.5
SS3/SS5 Source Current
-50
-100
-160
VDD Shunt Current
%
V
2.5
Load Regulation
%/V
0.03
18
20
Line Regulation
mV
VDD Shunt Setpoint
80
100
120
V
Current-Limit Voltage
UNITS
13
14
MIN
TYP
MAX
VDD Regulation Setpoint
PARAMETER
3.17
3.35
3.46
3.32
3.50
3.60
0mV < (CS3-FB3) < 70mV, 6V < V + < 30V
(includes load and line regulation)
V
3.46
3.65
3.75
FB3 Output Voltage
MAX783
MAX783R
MAX783S
3.3V AND 5V STEP-DOWN CONTROLLERS
15V FLYBACK CONTROLLER
PCMCIA REGULATORS (Note 1)
MAX783
Triple-Output Power-Supply Controller
for Notebook Computers
_______________________________________________________________________________________
3
PARAMETER
Quiescent Power Consumption
(both controllers on)
MIN
TYP
MAX
5.2
8.6
UNITS
mW
Input Current
Off V+ Current
1
A
REF Fault Lockout Voltage
30
60
S
--
H
--
D
--
N
, ON3, ON5, DA0, DA1, DB0, DB1, V
IN
= 0V or 5V
2.4
3.2
V
REF Output Voltage
3.24
3.36
A
V
VL - 0.5
4.2
4.7
V
V
SYNC
Input High Voltage
2.4
REF Load Regulation
30
75
mV
S
--
H
--
D
--
N
, ON3, ON5, DA0, DA1, DB0, DB1
D1, D2 Trip Voltage
Shutdown V+ Current
Input Low Voltage
0.8
25
40
1.61
1.69
A
Standby V+ Current
V
V
70
110
A
D1, D2 Input Current
S
--
H
--
D
--
N
, ON3, ON5, DA0, DA1, DB0, DB1, SYNC
100
nA
Q1, Q2 R
--
D
--
Y
--
5
Source Current
VL Output Voltage
12
20
30
A
Q1, Q2 R
--
D
--
Y
--
5
Sink Current
92
95
200
500
1000
%
A
Q1, Q2, R
--
D
--
Y
--
5
Output High Voltage
SYNC = 0V or 5V
VH - 0.5
V
Q1, Q2, R
--
D
--
Y
--
5
Output Low Voltage
Maximum Duty Cycle
4.5
5.5
V
89
92
0.4
V
Quiescent VH Current
VL Fault Lockout Voltage
4
10
A
SYNC = 3.3V
3.6
4.2
V
Oscillator SYNC Range
Oscillator Frequency
240
350
270
300
330
kHz
170
200
230
kHz
CONDITIONS
D1 = D2 = D3 = DA0 = DA1 = DB0 = DB1 = 0V,
FB5 = CS5 = 5.25V, FB3 = CS3 = 3.5V
FB5 = CS5 = 5.25V, VL switched over to FB5
Falling edge
No external load (Note 2)
Rising edge of FB5, hysteresis = 1%
SYNC Rise/Fall Time
0mA < I
L
< 5mA (Note 3)
Falling edge, hysteresis = 1%
S
--
H
--
D
--
N
= D1 = D2 = ON3 = ON5 = DA0 = DA1 = DB0 =
DB1 = 0V, V+ = 30V
D1 = D2 = ON3 = ON5 = DA0 = DA1 = DB0 = DB1 = 0V,
V+ = 30V
D1 = D2 = 0V to 5V
VH = 15V, V
OUT
= 2.5V
VH = 15V, V
OUT
2.5V
I
SOURCE
= 5A, VH = 3V
ON5 = ON3 = 0V, 5.5V < V+ < 30V, 0mA < I
L
< 25mA
I
SINK
= 20A, VH = 3V
VH = 18V, D1 = D2 = 5V, no external load
Falling edge, hysteresis = 1%
SYNC = 3.3V
SYNC = 0V or 5V
200
ns
Not tested
SYNC Low Pulse Width
200
ns
SYNC High Pulse Width
200
ns
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I
VL
= I
REF
= 0mA, S
--
H
--
D
--
N
= ON3 = ON5 = 5V, other digital input levels are 0V or +5V,
T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
VL/FB5 Switchover Voltage
(also R
--
D
--
Y
--
5
Trip Voltage)
INTERNAL REGULATOR AND REFERENCE
COMPARATORS
OSCILLATOR AND INPUTS/OUTPUTS
MAX783
Triple-Output Power-Supply Controller
for Notebook Computers
4
_______________________________________________________________________________________
Note 1:
Output current is further limited by maximum allowable package power dissipation.
Note 2:
Because the reference uses VL as its supply, the REF line regulation error is insignificant.
Note 3:
The main switching outputs track the reference voltage. Loading the reference reduces the main outputs slightly according
to the closed-loop gain (AV
CL
) and the reference voltage load regulation error. AV
CL
for the +3.3V supply is unity gain.
AV
CL
for the +5V supply is 1.54.
MAX183 5
50
1m
60
100
10
80
70
10m
1
90
100m
EFFICIENCY (%)
+5V OUTPUT CURRENT (A)
EFFICIENCY vs.
+5V OUTPUT CURRENT
V+ = 15V
N1-N4 = IRF7101
ON3 = LOW
F = 200kHz
V+ = 6V
MAX183 6
50
1m
60
100
10
80
70
10m
1
90
100m
EFFICIENCY (%)
+3.3V OUTPUT CURRENT (A)
EFFICIENCY vs.
+3.3V OUTPUT CURRENT
V+ = 15V
N1-N4 = IRF7101
ON3 = ON5 = HIGH
F = 200kHz
V+ = 6V
500
0
0
5
20
MAXIMUM +15V VDD OUTPUT CURRENT vs.
SUPPLY VOLTAGE
100
200
SUPPLY VOLTAGE (V)
MAXIMUM +15V LOAD CURRENT (mA)
10
15
VDD
>
+13V
+3.3V REGULATING
+3.3V LOAD = 0A
+3.3V LOAD = 3A
300
400
QUIESCENT SUPPLY CURRENT vs.
SUPPLY VOLTAGE
QUIESCENT SUPPLY CURRENT (mA)
0
1
2
13
14
0
6
12
18
24
30
SUPPLY VOLTAGE (V)
ON3 = ON5 = HIGH
STANDBY SUPPLY CURRENT vs.
SUPPLY VOLTAGE
STANDBY SUPPLY CURRENT (mA)
0
0.5
1.0
1.5
2.0
2.5
0
6
12
18
24
30
ON3 = ON5 = 0V
SUPPLY VOLTAGE (V)
__________________________________________Typical Operating Characteristics
(Circuit of Figure 1, Transpower TTI5902 transformer, T
A
= +25C, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
DL3/DL5 Sink/Source Current
V
OUT
= 2V
1
A
DH3/DH5 Sink/Source Current
BST3-LX3 = BST5-LX5 = 4.5V, V
OUT
= 2V
1
A
DL3/DL5 On-Resistance
High or low
7
DH3/DH5 On-Resistance
High or low, BST3-LX3 = BST5-LX5 = 4.5V
7
MIN
TYP
MAX
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I
VL
= I
REF
= 0mA, S
--
H
--
D
--
N
= ON3 = ON5 = 5V, other digital input levels are 0V or +5V,
T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
MAX783
Triple-Output Power-Supply Controller
for Notebook Computers
_______________________________________________________________________________________
5
MINIMUM VIN TO VOUT DIFFERENTIAL
vs. +5V OUTPUT CURRENT
MINIMUM V
IN
TO V
OUT
DIFFERENTIAL (V)
+5V OUTPUT CURRENT (A)
0
0.2
0.4
0.6
0.8
1.0
1m
10m
100m
1
10
300kHz
200kHz
+5V OUTPUT
STILL REGULATING
1000
0.1
100
10m
1
SWITCHING FREQUENCY vs.
LOAD CURRENT
10
LOAD CURRENT (A)
SWITCHING FREQUENCY (kHz)
100
1m
100m
SYNC = REF (300kHz)
ON3 = ON5 = HIGH
+5V, V
IN
= 7.5V
1
+5V, V
IN
= 30V
+3.3V, V
IN
= 7.5V
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 1, Transpower TTI5902 transformer, T
A
= +25C, unless otherwise noted.)
SHUTDOWN SUPPLY CURRENT vs.
SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT (
A)
0
100
200
300
400
500
0
6
12
18
24
30
SUPPLY VOLTAGE (V)
SHDN = 0V
I
LOAD
= 1A
V
IN
= 16V
PULSE-WIDTH MODULATION MODE WAVEFORMS
LX VOLTAGE
10V/div
+5V OUTPUT
VOLTAGE
50mV/div
500ns/div
I
LOAD
= 100mA
V
IN
= 10V
IDLE-MODE WAVEFORMS
+5V OUTPUT
50mV/div
2V/div
200
s/div
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