Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - DC/DC voltage regulator Switched-capacitor voltage converter SOIC 8

General Description

The MAX889 inverting charge pump delivers a regulated

negative output voltage at loads of up to 200mA. The

device operates with inputs from 2.7V to 5.5V to produce

an adjustable, regulated output from -2.5V to -V

The MAX889 is available with an operating frequency of

2MHz (T version), 1MHz (S version), or 0.5MHz (R ver-

sion). The higher switching frequency devices allow the

use of smaller capacitors for space-limited applica-

tions. The lower frequency devices have lower quies-

cent current.

The MAX889 also features a 0.1µA logic-controlled

shutdown mode and is available in an 8-pin SO pack-

age. An evaluation kit, MAX889SEVKIT, is available.

________________________Applications

TFT Panels

Hard Disk Drives

Camcorders

Digital Cameras

Measurement Instruments

Battery-Powered Applications

Features

♦ 200mA Output Current

♦ Up to 2MHz Switching Frequency

♦ Small Capacitors (1µF)

♦ +2.7V to +5.5V Input Voltage Range

♦ Adjustable Regulated Negative Output

(-2.5V to -V

)

♦ 0.1µA Logic-Controlled Shutdown

♦ Low 0.05Ω Output Resistance (in regulation)

♦ Soft-Start and Foldback Current Limited

♦ Short-Circuit and Thermal Shutdown Protected

♦ 8-Pin SO Package

MAX889

High-Frequency, Regulated,

200mA, Inverting Charge Pump

________________________________________________________________ Maxim Integrated Products 1

SHDN

OUTCAP-

AGND

FBCAP+

GND

TOP VIEW

MAX889

Pin Configuration

MAX889

INPUT +2.7V TO +5.5V

REGULATED

NEGATIVE

OUTPUT

(UP TO -1 × V

UP TO 200mA)

OUT

GNDAGND

CAP+

OFF

SHDN

CAP-

Typical Operating Circuit

19-1774; Rev 0; 7/00

For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

Ordering Information

PART

TEMP.

RANGE

PIN-

PACKAGE

SWITCHING

FREQUENCY

MAX889TESA -40°C to +85°C

8 SO 2MHz

MAX889SESA -40°C to +85°C

8 SO 1MHz

MAX889RESA -40°C to +85°C

8 SO 0.5MHz

EVALUATION KIT

AVAILABLE

Summary of content (8 pages)

PAGE 1
9-1774; Rev 0; 7/00 KIT ATION EVALU LE B A IL A AV High-Frequency, Regulated, 200mA, Inverting Charge Pump Features ♦ 200mA Output Current ♦ Up to 2MHz Switching Frequency ♦ Small Capacitors (1µF) ♦ +2.7V to +5.5V Input Voltage Range ♦ Adjustable Regulated Negative Output (-2.5V to -VIN) ♦ 0.1µA Logic-Controlled Shutdown ♦ Low 0.
PAGE 2
MAX889 High-Frequency, Regulated, 200mA, Inverting Charge Pump ABSOLUTE MAXIMUM RATINGS IN to GND .................................................................-0.3V to +6V FB, SHDN, CAP+ to GND ............................-0.3V to (VIN + 0.3V) AGND to GND .......................................................-0.3V to +0.3V OUT to GND .............................................................-6V to +0.3V CAP- to GND ............................................(VOUT - 0.3V) to +0.
PAGE 3
High-Frequency, Regulated, 200mA, Inverting Charge Pump (VIN = V SHDN = +5V, capacitors from Table 1, TA = -40°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN MAX UNITS Supply Voltage Range VIN RLOAD = 100Ω 2.7 5.5 V Output Voltage Range VOUT R LOAD = 100Ω -2.5 -VIN V IOUT(MAX)1 VIN = 5V, VOUT = -3.3V 200 IOUT(MAX)2 VIN = 3.3V, VOUT = -2.
PAGE 4
Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = V SHDN = +5V, capacitors from Table 1, TA = +25°C, unless otherwise noted.) 30 COUT = 4.7µF 20 10 MAX889R COUT = 10µF 0 70 60 50 MAX889T MAX889S 40 90 50 100 150 200 250 300 70 60 40 30 20 20 10 10 350 MAX889T MAX889S 50 30 0 0 0 100 200 300 400 0 500 50 100 150 200 350 FREE-RUN OUTPUT RESISTANCE vs. INPUT VOLTAGE FREE-RUN OUTPUT RESISTANCE vs. TEMPERATURE QUIESCENT SUPPLY CURRENT vs.
PAGE 5
High-Frequency, Regulated, 200mA, Inverting Charge Pump PIN NAME FUNCTION 1 IN Power-Supply Positive Voltage Input 2 CAP+ Positive Terminal of Flying Capacitor 3 GND Power Ground 4 CAP- Negative Terminal of Flying Capacitor 5 OUT Inverting Charge-Pump Output 6 SHDN Shutdown Control Input. Drive SHDN low to shut down the MAX889. Connect SHDN to IN for normal operation. 7 FB Feedback Input.
PAGE 6
MAX889 High-Frequency, Regulated, 200mA, Inverting Charge Pump (ESR) of the flying and output capacitors. The typical output impedance is more accurately determined from the Typical Operating Characteristics. pump switching halts. Connect SHDN to IN or drive high for normal operation. Current Limit and Soft-Start The MAX889 features thermal shutdown with hysteresis for added protection against fault conditions.
PAGE 7
High-Frequency, Regulated, 200mA, Inverting Charge Pump Capacitor Selection The appropriate capacitors used with the MAX889 depend on the switching frequency. Table 1 provides suggested values for CIN, CFLY, and COUT. Surface-mount ceramic capacitors are preferred for CIN, COUT, and CFLY due to their small size, low cost, and low ESR. To ensure proper operation over the entire temperature range, choose ceramic capacitors with X7R (or equivalent) low-temperature-coefficient (tempco) dielectrics.
PAGE 8
Table 1. Capacitor Selection Table PART FREQUENCY CFLY COUT CIN REGULATED CIN FREE-RUN MAX889R 0.5MHz 4.7µF 22µF 22µF 4.7µF MAX889S 1MHz 2.2µF 10µF 10µF 2.2µF MAX889T 2MHz 1µF 4.7µF 4.7µF 1µF Table 2.