SA58646 Datasheet, PDF (11/42 Pages) NXP Semiconductors – UHF 900 MHz transceiver IC

NXP Semiconductors
SA58646
UHF 900 MHz transceiver IC
Example: RF RX f = 903 MHz, VCO RX f = 892.3 MHz, IF f = 10.7 MHz, VCO TX
f = 925.6 MHz and the internal comparison frequency f = 20 kHz (f_xtal = 10.24 MHz):
REF_DIV[9:0] = 512 (10 0000 0000),
For RX: M = 892.3 × 10⁶ / 20 × 10³ = 44615, C = 697 (10 1011 1001), R = 7 (00 0111),
For TX: M = 925.6 × 10⁶ / 20 × 10³ = 46280, C = 723 (10 1101 0011), R = 8 (00 1000).
VCOs and varicaps are integrated. The total equivalent inductance is comprised of the
bonding wires, lead frame of the package and external inductors. External inductors can
be done with printed transmission lines on the PCB, which allows substantial savings.
An on-chip selectable voltage doubler is provided to enable a larger tuning range of the
VCOs.
The phase detectors have current drive type outputs. Current can be chosen between
400 µA and 800 µA.
XTALO
XTALI
XTAL_H
XTAL
XTAL_TUN
[3:0]
CLK_DIV
[2:0]
CLKO
CLOCK
DIVIDER
CLKO
VCP
GNDVCP
VOLTAGE
DOUBLER
10-BIT
REFERENCE
DIVIDER
REF_DIV
[9:0]
DOUBLER
VREG
VB
VOLTAGE
REGULATOR
REG_ADJ
[2:0]
REG
Fig 5. Synthesizer part
RX_CP
RX PHASE
DETECTOR
RXPD
RX_MDIV
[9:0]
mixer
RX_PRE
[5:0]
VCO
RX
10-BIT
6-BIT
MAIN RX PRESCALER
DIVIDER
RX
VREG
RX
TX PHASE
DETECTOR
TX_CP
TX_MDIV
[9:0]
TX_PRE
[5:0]
VCO
TX
10-BIT
6-BIT
MAIN TX PRESCALER
DIVIDER
TX
VREG
TX
PA MODO
RXLOX
RXLF
RXLOY
VRX
TXPD
TXLOX
TXLF
TXLOY
VTX
001aaf620
SA58646_1
Product data sheet
Rev. 01 — 8 February 2007
© NXP B.V. 2007. All rights reserved.
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