High-Accuracy Step-Down Controller

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,

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

Operating Temperature Range

MAX798ESE....................................................-40°C to +85°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10sec) .............................+300°C

Rising edge, hysteresis = 25mV

Rising edge, hysteresis = 15mV

CSH - CSL, negative

CSH - CSL, positive

6V < V+ < 30V

External resistor divider

CSH - CSL = 40mV,

SKIP = VL

0mV < (CSH - CSL) < 80mV,

SKIP = VL

CONDITIONS

V

4.2

4.7

VL/CSL Switchover Voltage

V

3.8

4.0

VL Fault Lockout Voltage

V

4.75

5.25

VL Output Voltage

mA

2.0

SS Fault Sink Current

µA

2.0

4.0

6.5

SS Source Current

V

4.5

30

Input Supply Range

-40

-100

-160

mV

80

100

120

Current-Limit Voltage

%/V

0.04

0.05

Line Regulation

V

1.6

6

Nominal Adjustable Output

Voltage Range

V

1.576

1.6

1.624

Feedback Voltage

%

±0.4

Load Regulation

UNITS

MIN

TYP

MAX

PARAMETER

No external load (Note 1)

V

2.463

2.505

2.537

Reference Output Voltage

Falling edge

V

1.8

2.3

Reference Fault Lockout Voltage

mV

20

Reference Load Regulation

SHDN = 0V, CSL = 6V, V+ = 0V or 30V, VL = 0V

µA

0.1

1

CSL Shutdown Leakage Current

SHDN = 0V, V+ = 30V, CSL = 0V or 6V

µA

15

V+ Shutdown Current

FB = CSH = CSL = 6V, VL switched over to CSL

µA

15

V+ Off-State Leakage Current

V+ = 4V, CSL = 0V (Note 2)

mW

6.6

10.5

Dropout Power Consumption

CSH = CSL = 6V

mW

6.4

8.5

Quiescent Power Consumption

STEP-DOWN CONTROLLER

INTERNAL REGULATOR AND REFERENCE