TX4915 View Datasheet(PDF) - Unspecified
Part Name
Description
Manufacturer
TX4915 Datasheet PDF : 9 Pages
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the wireless IC company
Fig. 1 – PFD input/output waveforms
fR
fV
DO
high-Z high-Z
LD
high-Z
Transmitte on
high-Z
TX4915
Power Amplifier
A two-stage amplifier consisting of a driver and an open collector final stage. The PAOUT open collector
output requires an external pull up coil to provide bias. The coil is part of the tuning and matching LC circuit
to get best performance with the external loop antenna. To achieve the best power amplifier efficiency the
high frequency voltage swing at the PAOUT pin should be two times the supply voltage. The power ampli-
fier has its own ground pin (VSS,VSS1) in order to reduce the aount of coupling to the other circuits.
The device is an ASK/OOK transmitted, with the data provided at the MODIN pin. When the MODIN is a
high logic level, the carrier is transmitted. When MODIN is a low logic level, then the carrier is not transmit-
ted.
Power Mode
The IC provides three power modes, the POWER DOWN MODE, the PLL ENABLE MODE and the
TRANSMIT MODE. How to get in this modes is described in the table below.
TXEN
L
H
H
MODIN
X
L
H
POWER DOWN MODE
PLL ENABLE MODE
TRANSMIT MODE
Page 6
March 2000
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