Step-Down Controllers with

Synchronous Rectifier for CPU Power

2

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ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

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.

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

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

Rising edge, hysteresis = 25mV

Rising edge, hysteresis = 15mV

Falling edge, hysteresis = 20mV (MAX799)

CSH-CSL, negative

CSH-CSL, positive

Falling edge, hysteresis = 15mV (MAX796)

6V < V+ < 30V

25mV < (CSH-CSL) < 80mV

0mV < (CSH-CSL) < 80mV, FB = VL, 6V < V+ < 30V,

includes line and load regulation

External resistor divider

(CSH-CSL) = 0V

0mV < (CSH-CSL) < 80mV

CONDITIONS

V

4.2

4.7

VL/CSL Switchover Voltage

V

3.8

4.1

VL Fault Lockout Voltage

V

4.7

5.3

VL Output Voltage

-0.05

0

0.05

V

2.45

2.505

2.55

SECFB Regulation Setpoint

mA

2.0

SS Fault Sink Current

µA

2.5

4.0

6.5

SS Source Current

5.0

30

V

4.5

30

Input Supply Range

-50

-100

-160

mV

80

100

120

Current-Limit Voltage

%/V

0.04

0.06

Line Regulation

1.5

V

4.85

5.10

5.25

5V Output Voltage (CSL)

V

REF

6

Nominal Adjustable Output

Voltage Range

V

2.43

2.505

2.57

Feedback Voltage

%

2.5

Load Regulation

UNITS

MIN

TYP

MAX

PARAMETER

MAX79_C

MAX79_E/M

0mV < (CSH-CSL) < 80mV, FB = 0V, 4.5V < V+ < 30V,

includes line and load regulation

V

3.20

3.35

3.46

3.3V Output Voltage (CSL)

+3.3V AND +5V STEP-DOWN CONTROLLERS

FLYBACK/PWM CONTROLLER

INTERNAL REGULATOR AND REFERENCE