SA58646 Datasheet, PDF (8/42 Pages) NXP Semiconductors – UHF 900 MHz transceiver IC

NXP Semiconductors
SA58646
UHF 900 MHz transceiver IC
Table 4. Activated blocks
Circuit block
Mode
Active
RX
Crystal active^[1]
X
X
Clock output not disabled
X
X
Voltage regulator active^[2]
X
X
Power amplifier active
X
-
Doubler enabled^[3]
X
X
Hard limiter or automatic level control not X
-
disabled
Earpiece amplifier enabled
X
X
Inactive
X
X
X
-
X
-
-^[4]
[1] In RX and TX mode, the crystal oscillator is automatically activated. An external frequency can be forced to
pins XTALI and XTALO.
[2] In RX and TX mode, the voltage regulator with adjustment is automatically enabled; bit REG can be either
logic 1 or logic 0.
[3] If the voltage doubler is enabled, the crystal oscillator is automatically activated.
[4] In Inactive mode, the earpiece amplifier is automatically disabled.
7.1.3 Control bits in power saving modes
Table 5 shows the control bit values for selection of each mode and the typical current
consumption for those modes.
Table 5. Control bit values
V_CC = 3.3 V; T_amb = 25 °C; f_xtal = 10.24 MHz.
Power saving MODE[1:0] Conditions
mode
Bit 1 Bit 0 Voltage Crystal
doubler oscillator
Voltage
regulator
Active mode 1
1
-
-
-
RX mode
1
0
-
-
-
Inactive mode 0
X
inactive disabled
disabled
XTAL_H = 0
XTAL_H = 1
inactive XTAL_H = 1 enabled
active
Clock
output
-
-
disabled
disabled
Typical
current
consumption
76 mA
58 mA
< 10 µA
210 µA
300 µA
550 µA
690 µA
When the clock output is activated, an extra power consumption is applied which is
proportional to the programmed bit CLKO. If bit XTAL_H = 0, then the crystal loss is less
than 50 Ω to ensure reliable start-up.
Table 6. Extra power consumption
Divider ratio
Extra current consumption
Bits CLK_DIV[2:0]
Bit CLKO = 0
XXX (1, 2, 2.5, 4, 128)
520 µA
000 (off)
0 µA
Bit CLKO = 1
350 µA
0 µA
SA58646_1
Product data sheet
Rev. 01 — 8 February 2007
© NXP B.V. 2007. All rights reserved.
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