Step-Down Controllers with
Synchronous Rectifier for CPU Power
MAX796/MAX797/MAX799
ABSOLUTE MAXIMUM RATINGS
V+ to GND .................................................................-0.3V, +36V
GND to PGND........................................................................±2V
VL to GND ...................................................................-0.3V, +7V
BST to GND ...............................................................-0.3V, +36V
DH to LX...........................................................-0.3V, BST + 0.3V
LX to BST.....................................................................-7V, +0.3V
SHDN to GND............................................................-0.3V, +36V
SYNC, SS, REF, FB, SECFB, SKIP, DL to GND..-0.3V, VL + 0.3V
CSH, CSL to GND .......................................................-0.3V, +7V
VL Short Circuit to GND..............................................Momentary
REF Short Circuit to GND ...........................................Continuous
VL Output Current ...............................................................50mA
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 8.70mW/°C above +70°C) ........................696mW
Plastic DIP (derate 10.53mW/°C above +70°C) .........842mW
CERDIP (derate 10.00mW/°C above +70°C) ..............800mW
Operating Temperature Ranges
MAX79_C_ _ ......................................................0°C to +70°C
MAX79_E_ _....................................................-40°C to +85°C
MAX79_MJE .................................................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .....................................+300
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
(V+ = 15V, GND = PGND = 0V, I VL = I REF = 0A, T
A
= 0°C to +70°C for MAX79_C, T
A
= 0°C to +85°C for MAX79_E,
T
A
= -55°C to +125°C for MAX79_M, unless otherwise noted.)
PARAMETER
+3.3V AND +5V STEP-DOWN CONTROLLERS
Input Supply Range
5V Output Voltage (CSL)
3.3V Output Voltage (CSL)
Nominal Adjustable Output
Voltage Range
Feedback Voltage
Load Regulation
Line Regulation
Current-Limit Voltage
SS Source Current
SS Fault Sink Current
FLYBACK/PWM CONTROLLER
SECFB Regulation Setpoint
Falling edge, hysteresis = 15mV (MAX796)
Falling edge, hysteresis = 20mV (MAX799)
SHDN = 2V, 0mA < I
VL
< 25mA, 5.5V < V+ < 30V
Rising edge, hysteresis = 15mV
Rising edge, hysteresis = 25mV
2.45
-0.05
4.7
3.8
4.2
2.505
0
2.55
0.05
5.3
4.1
4.7
V
MAX79_C
MAX79_E/M
0mV < (CSH-CSL) < 80mV, FB = VL, 6V < V+ < 30V,
includes line and load regulation
0mV < (CSH-CSL) < 80mV, FB = 0V, 4.5V < V+ < 30V,
includes line and load regulation
External resistor divider
(CSH-CSL) = 0V
0mV < (CSH-CSL) < 80mV
25mV < (CSH-CSL) < 80mV
6V < V+ < 30V
CSH-CSL, positive
CSH-CSL, negative
80
-50
2.5
2.0
4.5
5.0
4.85
3.20
REF
2.43
2.505
2.5
1.5
0.04
100
-100
4.0
0.06
120
-160
6.5
5.10
3.35
30
30
5.25
3.46
6
2.57
V
V
V
V
V
%
%/V
mV
µA
mA
CONDITIONS
MIN
TYP
MAX
UNITS
INTERNAL REGULATOR AND REFERENCE
VL Output Voltage
VL Fault Lockout Voltage
VL/CSL Switchover Voltage
V
V
V
2
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
