SX1223 SEMTECH [Semtech Corporation], SX1223 Datasheet - Page 18

• Manufacturer Part Number: SX1223
• Description: 425 - 475 MHz / 850 - 950 MHz Integrated UHF Transmitter
• Manufacturer: SEMTECH [Semtech Corporation]

(*) Assuming FreqBand=1. When FreqBand=0, the RF frequency is halved.
© Semtech 2007
Add
Add
Add
Add
Add
Add
Add
Add Bits VCO_freq1 VCO_freq0 Comments (*)
2
2
1
1
1
1
2
2
4-3
1-0
Bit XCO_quick_start XCO_high_current
Bit
Bit OL_opamp_en State
Bit
Bit PALDc_en Comments
Bit
Bit
3
2
5
1
0
2
LDO_en
LD_en
CP_HI
PA_C
0
1
0
1
0
1
0
1
0
1
0
0
1
1
0
1
0
0
1
1
Comments
LDO turned off, min/max VDD is 2.0/2.5 V
LDO turned on, min/max VDD is 2.2/3.6 V (default)
Comments
Startup time of PA controlled by internal capacitor; PTAT source using the
resistor connected to pin6 can be used (default)
Startup time of PA controlled by external capacitor connected to pin 6; PTAT
source using the resistor connected to pin6 is not available
Comments
PLL charge pump current is 125 µA (default)
PLL charge pump current is 500 µA
PA is only controlled by Mode1 and Mode0: PA on in transmit mode
(Mode1=Mode0=1) (default)
In transmit mode, PA is turned on/off by Lock Detect (i.e. LD=1 -> PA on)
State
LD off
LD on
Open loop opamp off
Open loop opamp on
(default)
0
1
0
1
Table 16: Low DropOut voltage regulator on/off
Setting for 850 MHz
Setting for 868 MHz
Setting for 915 MHz (default)
Setting for 950 MHz
Table 19: Lock Detect controlled PA
0
1
0
1
Table 17: Open loop opamp on/off
Table 21: Charge pump current
Table 15: XCO start-up control
Table 18: PA start-up control
Table 22: VCO frequency
Table 20: Lock Detector
Comments
Normal XCO bias current (default)
Higher XCO bias current
Quick start of XCO with normal bias current in steady state
Quick start of XCO with higher bias current in steady state
Comments
When opamp is enabled, a capacitor can be
added to the varactor pin that will increase the
transmission time in open loop modulation (mw2)
18
Comments
Output is low
A high indicate a PLL lock (default)
www.semtech.com
SX1223