Datasheet

DS_1x66B_001 73M1866B/73M1966B Data Sheet
Rev. 1.6 15
Pin
Number
Pin Name Type
Description
17 VND GND Negative digital ground
18 INT O Interrupt / ring detect (active low – open drain)
19
SCLK
I SPI clock
20 CS I SPI chip select (active low)
21
DR
I PCM transmit data sent to the D to A
22
SRE I Voltage regulator sense
23 SRB
O Voltage regulator drive
24
VBG
O VBG bypass, connect to 0.1μF capacitor to VNS
25 ACS
I AC current sense
26
VNS
GND Analog negative supply voltage
27
VPS PWRO Analog positive supply voltage (output)
28
RXP
I Receive plus – signal input
29
RXM
I Receive minus – signal input
30
TXM
O Transmit Minus
– transhybrid cancellation output
31
DCD
O
DC loop output
32 DCS I DC loop current sense
33
DCG
O DC loop control
34
DCI
I DC loop input
35
RGN
I Ring detect negative voltage input
36
RGP
I Ring detect positive voltage input
37
OFH
O Off-hook control
38
M20PB
I Test pin. Connect to VNX.
39
VNX
GND Negative supply voltage
40 SCP I/O Positive side of the secondary pulse transformer winding
41
MID
I/O
Charge pump midpoint
42
VPX
PWR Supply from the barrier
2.6 Requisite Use of Exposed Bottom Pad on 73M1866B and 73M1966B QFN
Packages
The exposed bottom pad is not intended for thermal relief (heat dissipation) and should not be
soldered to the PCB. Soldering of the exposed pad could also compromise electrical
isolation/insulation requirements for proper voltage isolation. Avoid any PCB traces or through-hole
vias on the PCB beneath the exposed pad area.