EVALUATION
KIT
AVAILABLE
TCM850
TCM851
TCM852
TCM853
1
REGULATED GaAs FET BIAS SUPPLY
FEATURES
s
s
s
Fixed – 4.1V or Adjustable – 0.5V to – 9V Output
at 5mA
4.5V to 10V Input Voltage Range
Low Output Voltage Ripple
TCM850-852 .............................................. 2mVp-p
TCM853 ...................................................... 1mVp-p
100kHz Charge Pump Switching Frequency
Optional External Synchronizing Clock
Input (TCM852)
Logic Level Shutdown Mode ................ 0.5
µ
A Typ.
Temperature (TCM850/852/853)
Low Cost, 8-Pin SOIC Package
GENERAL DESCRIPTION
The TCM850/1/2/3 combines an inverting charge pump
and a low noise linear regulator in a single small outline
package. They are ideal for biasing GaAS FETs in cellular
telephone transmitter power amplifiers
All four devices accept a range of input voltages from
4.5V to 10.0V and have – 5mA output current capability. The
TCM850/1/2 have both preset (– 4.1V) and variable (– 0.5V
to –9.0V) output voltages that program with an external
resistor divider. The TCM853 output voltage programs with
an external positive control voltage. The TCM850/1/3 can
be shutdown reducing quiescent current to less than
0.5µA (typ) over temperature, 2µA (typ) for the TCM851.
2
3
4
5
6
7
s
s
s
s
ORDERING INFORMATION
APPLICATIONS
s
s
s
s
s
Cellular Phones
Negative Regulated Power Supplies
LCD Bias Contrast Control
Adjustable GaAs FET Bias
Wireless Data Loggers
Part No.
TCM850COA
TCM850EOA
TCM851COA
TCM851EOA
TCM852COA
TCM852EOA
TCM853COA
TCM853EOA
TCM850EV
FUNCTIONAL BLOCK DIAGRAM
+
C
1
+
C
1
Package
8-Pin SOIC
8-Pin SOIC
8-Pin SOIC
8-Pin SOIC
Temp. Range
0°C to +70°C
– 40°C to +85°C
0°C to +70°C
– 40°C to +85°C
8-Pin SOIC
0°C to +70°C
8-Pin SOIC
– 40°C to +85°C
8-Pin SOIC
0°C to +70°C
8-Pin SOIC
– 40°C to +85°C
Evaluation Kit for
TCM850/1/2/3
C
1
–
C
1
CHARGE
PUMP
C
3
TCM850
TCM851
TCM852
IN
C
1
–
C
1
CHARGE
PUMP
C
3
TCM853
IN
NEGOUT
C
2
SHDN (TCM850)
SHDN (TCM851)
OSC (TCM852)
N
OUT
C
4
NEGOUT
C
2
N
C
4
OUT
– 1.28V
REF
GND
Figure 1.
TELCOM SEMICONDUCTOR, INC.
–
CONT
(CONTROL VOLTAGE)
GND
TC850/1/2/3-3 10/1/96
FB
(GND to SET
V
OUT
= – 4.1V)
SHDN
–
+
+
8
4-27
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
