AD9660KR Analog Devices Inc, AD9660KR Datasheet - Page 4

• Manufacturer Part Number: AD9660KR
• Description: IC LASER DIODE DRIVER 28-SOIC
• Manufacturer: Analog Devices Inc
• Type: Laser Diode Driverr

Specifications of AD9660KR

• Number Of Channels: 1
• Rohs Status: RoHS non-compliant
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 110mA
• Current - Modulation: 60mA
• Current - Bias: 90mA
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SOIC (0.300", 7.50mm Width)
• Mounting Type: Surface Mount
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Mounting: Surface Mount
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Compliant

AD9660
Pin
OUTPUT
BIAS LEVEL
BIAS CAL
BIAS HOLD
WRITE PULSE
WRITE CAL
WRITE LEVEL
WRITE HOLD
SENSE IN
GAIN
POWER
MONITOR
OFFSET
CURRENT SET determines offset current level. The input voltage at this node varies slightly with temperature and current, but is
OFFSET
PULSE
DISABLE
V
+V
GROUND
REF
S
Function
Analog laser diode current output. Connect to anode of laser diode, cathode connected to GROUND externally.
Analog voltage input, V
tion as follows:
TTL/CMOS compatible, Bias loop T/H control signal. Logic HIGH enables calibration mode, and the bias loop
T/H immediately goes into track mode. Logic LOW disables the bias loop T/H and immediately places it in hold
mode. WRITE PULSE should be held logic LOW while calibrating. Floats logic HIGH.
External hold capacitor for the bias loop T/H. Approximate droop in the bias current while BIAS CAL is logic
LOW is:
TTL/CMOS compatible, current control signal. Logic HIGH supplies I
LOW turns I
TTL/CMOS compatible, write loop T/H control signal. Logic HIGH enables calibration mode; before enabling
calibration the bias loop should be calibrated and OFFSET PULSE driven to an appropriate state. In calibration
mode, 13 ns after the WRITE PULSE goes logic HIGH, the write loop T/H goes into track mode (there is no de-
lay if WRITE PULSE is HIGH before WRITE CAL transitions to a HIGH level). The write loop T/H immedi-
ately goes into hold mode when the WRITE PULSE goes Logic LOW. WRITE CAL LOW disables the write
loop T/H and places it in hold mode. Floats logic HIGH.
Analog voltage input, V
tion as follows:
External hold capacitor for the write loop T/H. Approximate droop in I
logic LOW is:
Analog current input, I
of the PIN diode, with the PIN anode connected to GROUND or a negative voltage. Voltage at SENSE IN var-
ies slightly with temperature and current, but is typically 4.0 V.
External connection for the feedback network of the transimpedance amplifier. External feedback network, R
and C
Output voltage monitor of the internal feedback loop. Voltage is proportional to feedback current from photo
diode.
Set resistor connection for the offset current source. Resistor between OFFSET CURRENT SET and +V
typically 1.4 V. See curves. Can also be driven with a current out DAC.
TTL/CMOS compatible, OFFSET current control signal. Logic HIGH adds I
turns off I
TTL/CMOS compatible, current output disable circuit. Logic LOW for normal operation; logic HIGH disables
the current outputs to the laser diode, and drives the voltage on the hold capacitors close to V
output current when the device is re-enabled). DISABLE floats logic HIGH.
Analog Voltage Output, internal bandgap voltage reference, ~1.75 V, provided to user for power level offset.
Positive Power Supply. Nominally +5 V, pin connections should be tied together externally.
Ground Reference. All grounds should be tied together externally.
BW
GAIN
2 (550
OFFSET
, should be connected between GAIN and POWER MONITOR. See text for choosing values.
I
MODULATION
BIAS
I
. Floats logic HIGH.
MONITOR
I
) C
MODULATED
1
18 10
BIAS HOLD
MONITOR
REF
REF
C
off. Floats logic HIGH.
BIAS HOLD
to V
to V
–9
1.85 (R
V
I
t
WRITE LEVEL
, from PIN photo detector diode. SENSE IN should be connected to the cathode
REF
BIAS HOLD
REF
MONITOR
18 10
+ 1.6 V. Bias current is set proportional to the BIAS LEVEL during calibra-
+1.6 V. Write current is set proportional to the input voltage during calibra-
PIN DESCRIPTIONS
GAIN
C
WRITE HOLD
9
. Bandwidth of the loop is:
1.85
t
V
WRITE HOLD
–4–
BIAS LEVEL
V
50
REF
R
)
GAIN
. Bandwidth of the loop is:
V
50
REF
BW
MODULATION
MODULATION
2 (550 ) C
OFFSET
current while WRITE CAL is
to the laser diode. Logic
to I
1
OUT
BIAS HOLD
. Logic LOW
REF
(minimizes the
REV. 0
S
GAIN