AK2500B Datasheet, PDF (4/17 Pages) Asahi Kasei Microsystems – DS3/STS-1 Analog Line Receiver

ASAHI KASEI
PIN DESCRIPTION
[AK2500B]
No. Pin Name I/O
Function
Current reference output determined by the external resister.
1 IREF
O External resistance 4.9 kohm(+/-1%) should be connected between this pin and
VSSA.
Loss of Signal Threshold Control
2 LOSTHR
I
The voltage forced on this pin controls the input loss-of-signal threshold. Three
settings are provided by forcing GND, VDD/2, or VDD at LOSTHR (see Table
6).
Receive PLL Loss-of-Lock
3 RLOL
O Active High alarm. If the recovered clock frequency is larger than approximately
0.5% of EXCLK, RLOL alarm goes High.
Receive Input
4 RIN
I Unbalanced analog receive input. The B3ZS receive signal is input to this pins.
Data and clock are recovered and output on RPDATA, RNDATA and RCLK.
5 VDDA
6 VDDA
-
Power Supply for the analog part. +3.3 volts.
-
7 _RESET
8 BREF
9 TREF
10 VSSA
I Active low RESET. Pulled up to VDD with internal resister.
Bottom voltage reference level output.
O An external capacitor (0.1uF±20%) should be connected between this pin and
VSSA.
Top voltage reference level output.
O An external capacitor (0.1uF±20%) should be connected between this pin and
VSSA.
- Ground for the analog part. 0 volts.
11 VSSD
12 RLOS
13 EXCLK
14 VDDD
- Ground for the digital part. 0 volts.
O
Receive Loss-of-Signal.
This pin is set high on loss of the incoming signal at RIN.
External Reference Clock.
I
A valid DS3 or STS-1 clock must be provided at this input. The duty cycle of
EXCLK, referenced to VDD/2 levels, must be 40% - 60%. The EXCLK
frequency determines the operating frequency of the device.
- Power Supply for the digital part. +3.3 volts
15 VDDA
- Power Supply for the analog part. +3.3 volts.
16 VDDC
- Power Supply for the output buffer. +3.3 volts.
17 RCLK
O Recovered Clock.
18 RNDATA O Receive Negative Data.
19 RPDATA O Receive Positive Data.
20 VSSC
- Ground for the output buffer. 0 volts.
21 VSSA
22 VSSA
23 MODE1
24 MODE2
-
Ground for the analog part. 0 volts.
-
I
Mode Control.
Equalizer enable/bypass mode, Test mode are selectable as shown in
I _{Table 4.}
MS0005-E-00
-4-
1999/12