Pin settings ST7540
6/44
7 BU/THERM Digital/Output
Band in use/Thermal Shutdown event detection output.
In Rx mode:
"1" Signal within the programmed band
"0" No signal within the programmed band
In Tx mode:
"1" - Thermal Shutdown event occurred
"0" - No Thermal Shutdown event occurred
(signal not latched)
8 CLR/T Digital/Output
Synchronous mains access clock or
control register access clock
9
V
DD
Supply/Power Digital supply voltage or 3.3V voltage regulator output
10 MCLK Digital/Output Master clock output
11 RSTO Digital/Output Power ON or watchdog reset output
12 UART/SPI
Digital/Input
with internal pull-down
Interface type:
“0” - Serial peripheral interface
“1” - UART interface
13 WD
Digital/Input
with internal pull-up
Watchdog input. The internal watchdog counter is
cleared on the falling edges.
14 PA_IN- Analog/Input Power line amplifier inverting input
15 PA_OUT Power/Output Power line amplifier output
16
V
SS
Supply Power analog ground
17
V
CC
Supply Power supply voltage
18 PA_IN+ Analog/Input Power line amplifier not inverting input
19 TX_OUT Analog/Output Small signal analog transmit output
20
SV
SS
Supply Analog signal ground
21 X1 Analog/Output Crystal oscillator output
22 X2 Analog/Input Crystal oscillator input - or external clock input
23
V
SENSE
(1)
Analog/Input Output voltage sensing input for the voltage control loop
24
CL
(2)
Analog/Input
Current limiting feedback.
A resistor between CL and SV
SS
sets the PLI current
limiting value. An integrated 80pF filtering input
capacitance is present on this pin.
25 RX_IN Analog/Input Receiving analog input
26 VDC Power 5V voltage regulator output
27 TEST1
Digital/Input
with internal pull-down
Test input. Must be connected to GND.
28 TEST2 Analog/Input
Test input. Must be connected SV
SS
1. Cannot be left floating
2. Cannot be left floating
Table 1. Pin description (continued)
N° Name Type Description
