HDSP-420X Agilent(Hewlett-Packard), HDSP-420X Datasheet - Page 14

• Manufacturer Part Number: HDSP-420X
• Description: 20 mm (0.8 inch) Seven Segment Displays
• Manufacturer: Agilent(Hewlett-Packard)

HDMP-1512 (Tx), Signal Definitions
GND_LZHS
CAP0[A:B]
CAP1[A:B]
-ECLKSEL
GND_LOG
-COMGEN
GND_TTL
GND_LZ
Symbol
EWRAP
GND_A
LZMDF
FAULT
LZBTP
LZCSE
-LZON
LZDC
LZOUT
LOUT
Logic Ground
Laser Bandgap Test
Laser Current Source
Laser Driver Serial
Laser Monitor Diode
Laser Control and
Loop Filter Capacitor
Pins [79,80]
Loop Filter Capacitor
Pins [1,2]
Comma Generate
Pin [32]
External Clock Select
Pin [69]
Enable Wrap
Pin [71]
Laser Fault Indicator
Pin [29]
Analog Ground
Pins [3,4]
Pins [31,35,70,74]
Laser Ground
Pins [25,26]
Laser High Speed
Ground
Pins [10,18]
TTL Ground
Pins [39,40,65,66]
Local Serial Data
Pins [8,9]
Point
Pin [28]
Emitter
Pin [14]
Laser DC Drive
Pin [21]
Output
Pins [19,20]
Feedback
Pin [22]
Reset
Pin [30]
Signal Name
Output
Output
Input
Input
Input
Input
I/O
C
C
C
C
C
C
C
S
S
S
S
S
Logic Type
BLL
TTL
TTL
TTL
TTL
TTL
PLL filter capacitor should be connected from pins
79 and 80 to pins 1 and 2 (typical value = 0.01 F).
See Figures 18, 19, 20, and 21.
PLL filter capacitor should be connected from pins
79 and 80 to pins 1 and 2 (typical value = 0.01 F).
See Figures 18, 19, 20, and 21.
An active low input, causes the transmitter to
internally generate the positive disparity K28.5 byte
(0011111010) for transmission.
An active low input, selects the TBC inputs to be used
as the serial clock, bypassing the PLL. Used mainly
for testing.
Works in conjunction with TS1 and TS2 to specify
input and output ports.
Indicates the laser output level has moved outside of
the window detector set boundary and the laser test
capacitor (LZTC) has discharged to a fault level. This
output is reset by the -LZON pin.
Normally 0 volts. Used to provide a clean ground plane
for the critical PLL and high speed analog cells.
Normally 0 volts. Used for all internal PECL logic.
Should be completely isolated from the noisy TTL
ground.
Normally 0 volts. Used for all laser circuitry.
Normally 0 volts.
Normally 0 volts. Used for all TTL I/O buffer cells.
High speed data port, typically connected to the
port on the local receiver during serial wrap mode.
This pin is internally set to 2.3 VDC and normally
should connect to one terminal of the laser DC bias
resistor (pot1 Figure 3).
Used to set the bias current of the AC laser driver.
Typical use is shown in Figure 3 where pot2 is used to
set the laser modulation depth.
Used to control the laser diode DC bias (Figure 3).
AC driver to the laser diode. The outputs should be AC
coupled to the laser bias circuit.
Connects to the laser monitor diode and one terminal of
the laser DC bias resistor (pot1). Under normal
operating conditions, the voltage on this pin will
be 1.85 V.
The laser diode is turned on (active low) or off (high)
with this input. In the off state the capacitor on pin
LZTC charges, resetting the window
detector (Figure 3).
Description
LIN
669