Document
PRELIMINARY
SP8126B
High Speed Differential APC Amplifier
FEATURES ■ ■ ■ ■ ■ ■ ■ ■ Dual Wavelength Slew Rate of 300V/µs Fast Settling Time - 7ns Gain Control 2V Output Swing Low Offset Voltage: < 10mV Low Offset Drift: < 20µV/°C 12dB External Gain Adjust Range
VCC GAIN RGCOM GND 1 2 3 4 8 7 VOUT + VOUT RGAIN2 RGAIN1
SP8126B
8 Pin COB
6 5
APPLICATIONS ■ DVDRW ■ DVDRAM ■ CDRW
DESCRIPTION The SP8126B is a high-speed, differential output APC amplifier that integrates the photodiode and adjustable gain block on one chip. Independent gain control allows individual adjustment for 780mn and 650nm wavelength operation, as found in CD/DVD optical storage drives. This allows the user to control the laser power of the system in high-speed DVDRW, DVDRAM and CDRW systems. The wide 2V output swing also allows better system performance, through improved dynamic range.
GAIN VCC
+
Buffer
VOUT+ 1VP-P R1 500 R2 500 (Depend on FPC) 50pF 1k
GND
TIA
+
Gain Control
R3 500
(Flexible Flat Cable)
Buffer
VOUT1VP-P 50pF 1k
+
RGCOM
RGAIN1
RGAIN2
RG1 RG2
Figure 1. SP8126B Functional Diagram and Typical Application
Rev:B Date: 3/18/04 SP8126B High Speed Differential APC Amplifier © Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
TJ(MAX) ........................................................................................ 120°C VS(MAX) ............................................................................................... 6V VIN(MAX) .............................................................................................. 6V Power Supply Voltage Continuous Power Dissipation (TAMB = 70°C) COB (derate 13.3mW/°C above +70°C) ......... 90mW These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
ELECTRICAL SPECIFICATIONS
Unless otherwise noted: VCC = 5.0V, CLOAD = 50pF to GND, RLOADP = RLOADN = 1kΩ to GND, RGAIN = 510Ω (Nominal Gain), -20°C ≤ TA ≤ +85°C, Output measured differentially.
PARAMETER Supply Voltage Output Sensitivity Output Sensitivity vs. Temp Output Sensitivity vs. Vcc Input Optical Power Required to Produce 2V Output Swing Full Scale Linear Output Voltage Swing Output Common Mode Voltage
CONDITIONS
MIN 4.5
TYP 5 3000
MAX 5.5 3600 0.1 2
UNITS V V/W %/C %/V µW V
Laser Beam Diameter = 0.70mm, uniform density RGAIN=1230Ω RGAIN=1230Ω
2400
533 2 2.3 4.5V < Vcc < 5.5V Vcc/2.2 -10 RGAIN = 1230Ω (High Gain) -20 -25 RGAIN = 1230Ω (High Gain) -50
666 2.8 2.5 Vcc/2 0.5 1.0 -11 -13 1.6 2.4
800
2.7 Vcc/1.8 10 20 25 50 2 5
V V mV mV µV/C µV/C mVrms mVrms MHz MHz dB dB
Output Offset Voltage
Output Offset Voltage Drift
Output Noise
BW = 100MHz BW = 100MHz, RGAIN = 1230Ω (High Gain)
Bandwidth
-3dB -3dB, RGAIN = 1230Ω (High Gain)
70 50 55 50
100 68 76 73 7 12 10 15
PSRR
4.5V < Vcc.