Electrical characteristics (continued) – Rainbow Electronics MAX1775 User Manual

Page 3

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MAX1775

Dual-Output Step-Down

DC-DC Converter for PDA/Palmtop Computers

_______________________________________________________________________________________

3

ELECTRICAL CHARACTERISTICS (continued)

(V

IN

= +12V, V

MAIN

= V

INC

= V

CS-

= V

CS+

= +3.3V, V

CORE

= +1.8V, Circuit of Figure 4, T

A

= 0°C to +85°C, unless otherwise noted.

Typical values are at T

A

= +25°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

CORE REGULATOR

Input Voltage Range

V

INC

2.6

5.5

V

V

INC

rising

2.40

2.47

2.55

INC Undervoltage Lockout

V

INC

falling

2.30

2.37

2.45

V

Core Output Voltage Adjust
Range

1.0

5.0

V

Maximum Core Load Current

(Note 1)

1

1.5

A

FBC Regulation Threshold

V

FBC

V

INC

= +2.5 to +5.5V, I

OUTC

= 0 to 200mA

0.97

1.0

1.03

V

FBC Input Current

I

FBC

V

FBC

= +1.3V

-0.1

0.1

µA

Dropout Voltage (INC to LXC)

I

OUTC

= 400mA

0.1

0.25

V

LXC Leakage Current

I

LXC

V

INC

= +5.5V, V

LXC

= 0 to +5.5V

-10

10

µA

LXC P-Channel, N-Channel
On-Resistance

0.25

0.5

LXC P-Channel Current Limit

I

CLC

1200

1800

3000

mA

LXC P-Channel Minimum
Current

100

200

400

mA

LXC N-Channel Valley Current

900

1400

2400

mA

LXC N-Channel Zero-Crossing
Current

40

110

170

mA

LXC Dead Time

50

ns

Maximum Duty Cycle

100

%

Minimum On-Time

170

400

670

ns

Minimum Off-Time

170

400

670

ns

REFERENCE

Reference Voltage

V

REF

1.23

1.25

1.27

V

Reference Load Regulation

I

REF

= 0 to 50µA

10

mV

Reference Line Regulation

V

CS

- = +2.5V to +5.5V, I

REF

= 50µA

5

mV

Reference Sink Current

I

REF

10

µA

CVL, CVH REGULATORS

I

CVL

= 50mA, V

IN

= +2.7V, V

CS

- = 0

2.6

2.8

3.1

CVL Output Voltage

V

CVL

I

CVL

= 50mA, V

CS

- = +3.3V

3.2

V

CVL Switchover Threshold

V

CS-

rising, hysteresis = 100mV (typ)

2.40

2.47

2.55

V

V

IN

= +4V, I

CVH

= 25mA

V

IN

- 3.4 V

IN

- 2.8

CVH Output Voltage

V

CVH

V

IN

= +12V, I

CVH

= 50mA

V

IN

- 4.3 V

IN

- 3.7

V

CVH Switchover Threshold

V

IN

V

IN

rising, hysteresis = 350mV (typ)

5.5

V

V

CVL

rising

2.40

2.47

2.55

CVL Undervoltage Lockout

V

CVL

falling

2.30

2.37

2.45

V

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