MAX1795EUA maxim 美信芯片 电子元器件中文版规格手册.pdf

General Description

The MAX1795/MAX1796/MAX1797 are high-efficiency,

step-up DC-DC converters intended for small portable

hand-held devices. These devices feature Maxim’s True

Shutdown™ circuitry, which fully disconnects the out-

put from the input in shutdown, improves efficiency,

and eliminates costly external components. All three

devices also feature Maxim’s proprietary LX-damping

circuitry for reduced EMI in noise-sensitive applications.

also be adjusted to other voltages, using two external

resistors. The three devices differ only in their current

limits, allowing optimization of external components for

different loads: The MAX1795, MAX1796, and MAX1797

have current limits of 0.25A, 0.5A, and 1A, respectively.

All devices are packaged in a compact, 8-pin μMAX

package that is only 1.09mm tall and half the size of an

Features

● > 95% Efficiency

● 25μA Quiescent Supply Current

● Low-Noise Antiringing Feature

● LBI/LBO Comparator Enabled in Shutdown

● 2μA Shutdown Current

● 8-Pin μMAX Package

19-1798; Rev 0; 12/00

True Shutdown is a trademark of Maxim Integrated Products.

Pin Conguration Typical Operating Circuit

FB

LBI

SHDN

GND

LBI

LBO

BATT

FB

LX

OUT

OUT, LX, SHDN, LBI, LBO, BATT to GND ..............-0.3V to +6V

FB ........................................................... -0.3V to (V

+ 0.3V)

I

, I

Output Short-Circuit Duration .................................................. 5s

Continuous Power Dissipation

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

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

Minimum Input Voltage After startup 0.7 V

Operating Voltage V

(Note 1) 1.0 5.5 V

Startup Voltage T

= +25°C, R

= 3kΩ 0.85 1.0 V

Steady-State Output Current I

BATT = +2V,

FB = OUT

(V

= +3.3V)

MAX1795 100 180

mA

MAX1796 200 300

MAX1797 400 550

BATT = +2V,

FB = GND

MAX1796 100 200

V

= +2V to +5.5V 1.20 1.24 1.28 V

Feedback Input Current I

V

Internal NFET, PFET

On-Resistance

V

= +3.3V,

I

= 100mA

Ω

MAX1795 0.2 0.25 0.35

MAX1797 0.8 1.0 1.25

LX Leakage Current I

V

= 0 and +5.5V, V

= +5.5V 0.2 µA

Synchronous Rectier Turn-Off

Current Limit

25 mA

Damping Switch On-Resistance R

100 200 400 Ω

Operating Current into OUT