sx1231h Semtech Corporation, sx1231h Datasheet - Page 22

• Manufacturer Part Number: sx1231h
• Description: Low Power Integrated Uhf Transceiver With On-chip +20dbm Pa
• Manufacturer: Semtech Corporation

3.3.7. High Power Settings
The SX1231H has a high power +20 dBm capability on PA_BOOST pin, with the following settings:
Table 11 High Power Settings
Note
The Duty Cycle of transmission at +20dBm is limited to 1%, with a maximum VSWR of 3:1 at antenna port, over the
standard operating range [-40;+85°C]. For any other operating condition, contact your Semtech representative.
3.3.8. Output Power Summary
The curves below summarize the possible PA options on the SX1231H:
3.3.9. Over Current Protection
An over current protection block is built-in the chip. It helps preventing surge currents required when the transmitter is used
at its highest power levels, thus protecting the battery that may power the application. The current clamping value is
controlled by OcpTrim bits in RegOcp, and is calculated with the following formula:
Note
Rev 1 - Oct 2011
ADVANCED COMMUNICATIONS & SENSING
High Power settings MUST be turned off when using PA0, and in Receive mode
Imax sets a limit on the current drain of the Power Amplifier only, hence the maximum current drain of the
SX1231H is equal to Imax + I
RegTestPa1
RegTestPa2
Register
RegOcp
-10
-14
-18
-22
22
18
14
10
-2
-6
6
2
-18
Address
0x5A
0x5C
0x13
FS
-14
Imax
Figure 6. Output Power Curves
-10
=
High Power
45
Value for
+
0x5D
0x7C
0x0F
Pout vs. Programmed Power
-6
5 OcpTrim
×
Pr ogr am m e d Pow e r [dBm ]
Page 22
-2
(
Pout on PA0 [dBm]
Pout on PA1 [dBm]
Pout on PA1+PA2 [dBm]
Pout on PA1+PA2 with 20dBm settings [dBm]
Value for Rx
mA
or PA0 use
2
)
0x1x
0x55
0x70
6
10
OCP control
High power PA control
High power PA control
14
Description
18
SX1231H
DATASHEET
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