
XRT7295AT
3
Rev.1.20
PIN CONFIGURATION
VDDA
LOSTHR
REQB
ICT
GNDA
RIN
TMC1
LPF1
RPDATA
RNDATA
RCLK
EXCLK
LPF2
TMC2
RLOS
RLOL
VDDC
GNDD
VDDD
GNDC
20 Lead SOJ (Jedec, 0.300”)
20
1
11
10
2
3
4
5
6
7
15
14
13
12
17
16
8
9
19
18
PIN DESCRIPTION
Pin #
Symbol
Type
Description
1
GNDA
Analog Ground.
2
RIN
I
Receive Input.
Analog receive input. This pin is internally biased at about 1.5V in series
with 50 kW.
3,6
TMC1-TMC2
I
Test Mode Control 1 and 2
. Internal test modes are enabled within the device by using
TMC1 and TMC2. Users must tie these pins to the ground plane.
4,5
LPF1-LPF2
I
PLL Filter 1 and 2
. An external capacitor (0.1mF ±20%) is connected between these pins.
7
RLOS
O
Receive Loss-of-signal.
This pin is set high on loss of the data signal at the receive input.
(See Table 6)
8
RLOL
O
Receive PLL Loss-of-lock.
This pin is set high on loss of PLL frequency lock.
9
GNDD
Digital Ground for PLL Clock
. Ground lead for all circuitry running synchronously with
PLL clock.
10
GNDC
Digital Ground for EXCLK
. Ground lead for all circuitry running synchronously with
EXCLK.
11
VDDD
5V Digital Supply (±10%) for PLL Clock. Power for all circuitry running synchronously
with PLL clock.
12
VDDC
5V Digital Supply (±10%) for EXCLK. Power for all circuitry running synchronously with
EXCLK.
13
EXCLK
I
External Reference Clock
. A valid DS3 (44.736MHz ±100ppm) or STS-1 (51.84MHz +
100ppm) clock must be provided at this input. The duty cycle of EXCLK, referenced to VDD
/2 levels, must be within 40% - 60% with a minimum rise and fall time (10% to 90%) of 5ns.
14
RCLK
O
Receive Clock
. Recovered clock signal to the terminal equipment.
15
RNDATA
O
Receive Negative Data
. Negative pulse data output to the terminal equipment. (See
Figure 11.
)
16
RPDATA
O
Receive Positive Data
. Positive pulse data output to the terminal equipment. (See
Figure 11
)
17
ICT
I
In-circuit Test Control (Active-low)
. If ICT is forced low, all digital output pins (RCLK,
RPDATA, RNDATA, RLOS, RLOL) are placed in a high-impedance state to allow for in-cir-
cuit testing. There is an internal pull-up on this pin.
18
REQB
I
Receive Equalization Bypass
. A high on this pin bypasses the internal equalizer. A low
places the equalizer in the data path.
19
LOSTHR
I
Loss-of-signal Threshold Control
. The voltage forced on this pin controls the input loss-
of-signal threshold. Three settings are provided by forcing GND, VDD/2, or VDD. This pin
must be set to the desired level upon power-up and should not be changed during opera-
tion.
20
VDDA
5V Analog Supply (±10%).