DataSheet.es    


PDF TCM850 Data sheet ( Hoja de datos )

Número de pieza TCM850
Descripción REGULATED GaAs FET BIAS SUPPLY
Fabricantes TelCom Semiconductor 
Logotipo TelCom Semiconductor Logotipo



Hay una vista previa y un enlace de descarga de TCM850 (archivo pdf) en la parte inferior de esta página.


Total 7 Páginas

No Preview Available ! TCM850 Hoja de datos, Descripción, Manual

EVALUATION
KIT
AVAILABLE
1TCM850
TCM851
TCM852
TCM853
REGULATED GaAs FET BIAS SUPPLY
FEATURES
s Fixed – 4.1V or Adjustable – 0.5V to – 9V Output
at 5mA
s 4.5V to 10V Input Voltage Range
s Low Output Voltage Ripple
TCM850-852 .............................................. 2mVp-p
TCM853 ...................................................... 1mVp-p
s 100kHz Charge Pump Switching Frequency
s Optional External Synchronizing Clock
Input (TCM852)
s Logic Level Shutdown Mode ................ 0.5µA Typ.
Temperature (TCM850/852/853)
s 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
APPLICATIONS
s Cellular Phones
s Negative Regulated Power Supplies
s LCD Bias Contrast Control
s Adjustable GaAs FET Bias
s Wireless Data Loggers
FUNCTIONAL BLOCK DIAGRAM
ORDERING INFORMATION
Part No.
TCM850COA
TCM850EOA
TCM851COA
TCM851EOA
TCM852COA
TCM852EOA
TCM853COA
TCM853EOA
TCM850EV
Package
Temp. Range
8-Pin SOIC
8-Pin SOIC
8-Pin SOIC
8-Pin SOIC
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
4
5
C1+
C1
C1–
NEGOUT
C2
CHARGE
PUMP
N
TCM850
TCM851
TCM852
SHDN (TCM850)
SHDN (TCM851)
OSC (TCM852)
– 1.28V
REF
IN
C3
OUT
C4
C1+
C1
C1–
CHARGE
PUMP
TCM853
NEGOUT
C2
N
FB
(GND to SET
VOUT = – 4.1V)
SHDN
6
IN
C3
OUT
C4
7
CONT
(CONTROL VOLTAGE)
GND
TELCOM SEMICONDUCTOR, INC.
Figure 1.
GND
TC850/1/2/3-3 10/1/96
8
4-27

1 page




TCM850 pdf
REGULATED GaAs FET BIAS SUPPLY
1TCM850
TCM851
TCM852
TCM853
Shutdown Mode
Shutdown inputs are provided to reduce TCM850/1/3
supply current during idle periods. When the shutdown input
is in its active state, supply current over temperature is
reduced to 0.5µA (typ) TCM850/2/3 and 2µA (typ) TCM851.
All shutdown inputs are TTL level compatible: TCM850 and
TCM853 both have active low inputs (SHDN) while the
TCM851 has an active high input. The TCM852 can be
shutdown by setting the OSC input to a logic low level. The
TCM852 exits the shutdown state when the clock signal is
again restored.
Charge Pump Frequency Control
In applications where the charge pump switching fre-
quency may cause interference or filtering problems, it is
recommended the TCM852 be used. Switching frequency is
determined by a 50kHz to 250kHz square wave signal
applied to the OSC input. The signal applied to OSC can
have a duty cycle between 40% and 60%. *Note: an external
oscillator signal MUST be applied to the TCM852. The
TCM852 does not have an on-board oscillator truebase.
Capacitors
Capacitors with low effective series resistance (ESR)
should be used to maintain sufficient headroom across the
linear post regulator. Recommended values for C1, C2, and
C3 are 1µF, 0.8ESR. The recommended value for C4 is
10µF, 0.2. All capacitors should be either surface mount
chip tantalum, or chip ceramic types.
Board Layout
The TCM850/1/2/3 typically finds use in applications
where low output noise is important. To ensure good noise
performance, please observe the following basic layout
suggestions:
(1) Mount all components in the circuit as close together
as possible.
(2) Keep trace lengths short; especially those to control
inputs such as FB and CONT. This will reduce the
effect of parasitic capacitance and inductance.
(3) Minimize ground impedance by employing a ground
plane.
Noise and Ripple Measurement
The TCM850/1/2/3 charge pump switching action causes
small ground voltage differences between the TCM850/1/2
/3 circuit and the oscilloscope. These voltage differences
cause ground currents in the probe wires inducing voltage
spikes and result in erroneous readings. As a result, noise
and ripple measurements should be made directly across
output capacitor C4. Do not use the ground lead of the
oscilloscope probe. Instead, remove the plastic cover from
the probe tip and touch the probe ground ring directly to the
negative side of C4. Tektronix chassis mount test jack (part
number 131-0258) or a nail-type probe tip connect to the
probe and minimize noise and ripple measurement error.
2
3
Evaluation Kit
TelCom Semiconductor offers evaluation kit
(TCM850EV) for the TCM850-853. A second evaluation kit
(TC7660EV) evaluates several TelCom charge pumps in-
cluding the TC7660, TC7660S, TC7662B, TC962, TC682.
This kit also supports the TCM850 (but not the TCM851-
853).
4
5
6
7
TELCOM SEMICONDUCTOR, INC.
8
4-31

5 Page










PáginasTotal 7 Páginas
PDF Descargar[ Datasheet TCM850.PDF ]




Hoja de datos destacado

Número de piezaDescripciónFabricantes
TCM850REGULATED GaAs FET BIAS SUPPLYTelCom Semiconductor
TelCom Semiconductor
TCM850COAREGULATED GaAs FET BIAS SUPPLYTelCom Semiconductor
TelCom Semiconductor
TCM850EOAREGULATED GaAs FET BIAS SUPPLYTelCom Semiconductor
TelCom Semiconductor
TCM851REGULATED GaAs FET BIAS SUPPLYTelCom Semiconductor
TelCom Semiconductor

Número de piezaDescripciónFabricantes
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices


DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.


DataSheet.es    |   2020   |  Privacy Policy  |  Contacto  |  Buscar