MAX850 Datasheet, PDF (1/8 Pages) Maxim Integrated Products – Low-Noise, Regulated, Negative Charge-Pump Power Supplies for GaAsFET Bias

19-0238; Rev 2; 4/96
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Low-Noise, Regulated, Negative
Charge-Pump Power Supplies for GaAsFET Bias
_______________General Description
The MAX850–MAX853 low-noise, inverting, charge-
pump power supplies are ideal for biasing GaAsFETs in
cellular telephone transmitter amplifiers.
The MAX850–MAX852 offer both preset (-4.1V) and
adjustable (-0.5V to -9.0V) output voltages. The
MAX853 uses an external positive control voltage to set
the negative output voltage. Input voltage range for all
four devices is 4.5V to 10V. Output current is 5mA.
An internal linear regulator reduces the output voltage
ripple to 2mVp-p. With a well-filtered control voltage
(VCTRL), the MAX853 achieves typical output ripple of
less than 1mVp-p. Supply current is 3mA max, and
shutdown current is less than 1µA max over temperature
(5µA max for MAX851).
________________________Applications
Cellular Phones
Negative Regulated Power Supplies
Personal Communicators, PDAs
Wireless Data Loggers
Continuously Adjustable GaAsFET Bias
LCD-Bias Contrast Control
__________Typical Operating Circuit
VIN = 4.5V to 10.0V
(4 CELLS)
____________________________Features
o Fixed -4.1V or Adjustable -0.5V to -9V Output at 5mA
o 4.5V to 10V Input Voltage Range
o 2mVp-p Output Voltage Ripple (MAX850–MAX852)
1mVp-p Output Voltage Ripple (MAX853)
o 100kHz Charge-Pump Switching Frequency
(MAX850/MAX851/MAX853)
o External Synchronizing Clock Input (MAX852)
o Logic-Level Shutdown Mode: 1µA Max Over
Temperature (MAX850/MAX852/MAX853)
o Low Cost, 8-Pin SO Package
______________Ordering Information
PART
TEMP. RANGE
MAX850C/D
0°C to +70°C
MAX850ISA
-25°C to +85°C
MAX850ESA
-40°C to +850°C
MAX851C/D
0°C to +70°C
MAX851ISA
-25°C to +85°C
MAX851ESA
-40°C to +85°C
MAX852C/D
0°C to +70°C
MAX852ISA
-25°C to +85°C
MAX852ESA
-40°C to +85°C
MAX853C/D
0°C to +70°C
MAX853ISA
-25°C to +85°C
MAX853ESA
-40°C to +85°C
* Dice are specified at TA = +25°C only.
PIN-PACKAGE
Dice*
8 SO
8 SO
Dice*
8 SO
8 SO
Dice*
8 SO
8 SO
ise* ^Dice*
8 SO
8 SO
C1
C2
* MAX850: SHDN
MAX851: SHDN
MAX852: OSC
IN
C1+
C1-
MAX850
MAX851
OUT
MAX852
NEGOUT
SHDN*
SHDN
FB
OSC
GND
C3
VOUT = -4.1V
(VGG of GaAsFET)
C4
__________________Pin Configuration
TOP VIEW
C1+ 1
C1- 2
NEGOUT 3
SHDN* 4
(MAX850/853)
* SHDN (MAX851)
OSC (MAX852)
MAX850
MAX851
MAX852
MAX853
SO
8 IN
7 GND
6 OUT
5 FB**
(MAX850–852)
** CONT (MAX853)
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