MAX1673 Datasheet, PDF (1/8 Pages) Maxim Integrated Products – Regulated, 125mA-Output, Charge-Pump DC-DC Inverter

19-1334; Rev 0; 1/98
Regulated, 125mA-Output,
Charge-Pump DC-DC Inverter
________________General Description
The MAX1673 charge-pump inverter provides a low-
cost, compact means of generating a regulated nega-
tive output from a positive input at up to 125mA. It
requires only three small capacitors, and only two resis-
tors to set its output voltage. The input range is 2V to
5.5V. The regulated output can be set from 0V to -V_IN in
Skip regulation mode or -1.5V to -V_IN in Linear (LIN)
regulation mode.
In Skip mode, the MAX1673 regulates by varying its
switching frequency as a function of load current. This
On-Demand™ switching gives the MAX1673 two
advantages: very small capacitors and very low quies-
cent supply current. At heavy loads, it transfers energy
from the input to the output by switching at up to
350kHz. It switches more slowly at light loads, using
only 35µA quiescent supply current.
In Linear mode, the MAX1673 switches at a constant
350kHz at all loads and regulates by controlling
the current-path resistance. This provides constant-
frequency ripple, which is easily filtered for low-noise
applications.
This device also features a 1µA logic-controlled shut-
down mode and is available in a standard 8-pin SO
package. For a device that delivers about 10mA and
fits in a smaller package, refer to the MAX868.
________________________Applications
Hard Disk Drives
Camcorders
Measurement Instruments
Modems
Analog Signal-Processing Digital Cameras
Applications
____________________________Features
o Regulated Negative Output Voltage
(up to -1 x V_IN)
o 125mA Output Current
o 35µA Quiescent Supply Current
(Skip-mode regulation)
o 350kHz Fixed-Frequency, Low-Noise Output
(Linear-mode regulation)
o 2V to 5.5V Input Range
o 1µA Logic-Controlled Shutdown
_______________Ordering Information
PART
MAX1673ESA
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8 SO
Typical Operating Circuit
___________________Pin Configuration
TOP VIEW
LIN/SKIP 1
CAP+ 2
CAP- 3
SHDN 4
MAX1673
8 IN
7 GND
6 FB
5 OUT
INPUT 2V TO 5.5V
ON
OFF
SHDN ^IN
FB
MAX1673
CAP+
OUT
CAP-
LIN/SKIP GND
REGULATED
NEGATIVE
OUTPUT
(UP TO -1 x V_IN,
UP TO 125mA)
SO
On-Demand™ is a trademark of Maxim Integrated Products.
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone] ext. 3468.