Datasheet

DS_2901CE_031 73M2901CE Data Sheet
Rev. 3.4 7
3 Pin Descriptions
3.1 Power Pins
Pin Name Pin Number Type Description
VPA 10 I Positive analog voltage (analog supply)
VNA 16 I Negative analog voltage (analog ground)
VPD 2, 20, 25 I Positive digital voltage (digital supply)
VND 1, 17, 22 I Negative digital voltage (digital ground)
3.2 Analog Interface Pins
Pin Name Pin Number Type Description
RXA 15 I Receive analog input
TXAN 11 O Transmit analog - output
TXAP 12 O Transmit analog + output
VBG 14 O
Analog Band Gap voltage reference (0.1 µF to VNA). This pin
must not be connected to external circuitry other than the
decoupling capacitor.
VREF 13 O Analog reference voltage (0.1 µF to VNA)
3.3 Digital Interface Pins
Pin Name Pin Number Type Description
RESET 9 I Reset
RXCLK 27 O Receive data synchronous clock, valid on rising edge
TXCLK 24 O Transmit data synchronous clock, valid on rising edge
TXD 23 I Serial data input from DTE
RXD 26 O Serial output to DTE
USR10 8 I/O Programmable I/O port. This pin can optionally be used to
control an external switch for external Line In Use circuitry.
USR11 7 I/O Programmable I/O port. This pin can optionally be used to
control an external switch for caller ID operation.
RTS 6 I Request to send
CTS 5 O Clear to send
DSR 4 O Data set ready
DCD 3 O Data carrier detect
RI 32 O Ring indicator
RELAY 31 O Relay driver output
USR20 29 I/O Programmable I/O port