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Электронный компонент: T0800-TNQ

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Features
Current-controlled Output Current Source with 5 Input Channels
2 Selectable Outputs for Grounded Laser Diodes
Output Current per Channel up to 200 mA
Total Output Current up to 250 mA
Rise Time 1.0 ns/Fall Time 1.1 ns
On-chip RF Oscillator
Control of 2 Different Frequencies and Swings by Use of 4 External Resistors
Oscillator Frequency Range from 200 MHz to 600 MHz
Oscillator Swing to 100 mA
Single 5-V Power Supply
Common Enable/Disable Input
TTL/CMOS Control Signals
Small SSO24 Package and QFN28 Package
Applications
Combo Drives (DVD + CD-RW)
DVD-RAM with CD-RW Capability
DVD-RW with CD-RW Capability
1.
Description
The T0800 is a laser diode driver for the operation of two different, grounded laser
diodes for DVD-RAM (650 nm) and CD-RW (780 nm). It includes five channels for five
different optical power levels which are controlled by a separate IC. The read channel
generates a continuous output level. The channels 2 to 5 are provided as write chan-
nels with very fast switching speeds. When a low signal is applied to the NE pins, write
current pulses are enabled. All channels are summed together and switched to one of
the two outputs IOUTA or IOUTB by the select input SELA. Each channel can contrib-
ute up to 200 mA to the total output current of up to 250 mA. A total gain of 100 is
provided between each reference current input and the selected output. Although the
reference inputs are current inputs, voltage control is possible by using external resis-
tors. An on-chip RF oscillator reduces laser mode hopping noise during read mode.
Frequency and swing can be set independently for the two selectable outputs with two
pairs of resistors. Oscillation is enabled by a high signal at the ENOSC pin. Complete
output current and oscillator switch-off is achieved by a low signal at the ENABLE
input.
5-Channel Laser
Driver with RF
Oscillator and
2 Outputs
T0800
Rev. 4503DDVD02/05
2
4503DDVD02/05
T0800
2.
Pin Configuration
Figure 2-1.
Pinning SSO24
IR
I2
I3
I4
I5
RFA
RFB
NE2
NE3
NE4
NE5
ENABLE
VCC1
VCC2
IOUTA
IOUTA
GND
RSA
RSB
IOUTB
IOUTB
SELA
ENOSC
VCC2
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
Table 2-1.
Pin Description: SSO24
Pin
Symbol
Type
Function
1
IR
Analog
Input current, bias voltage approximately GND
2
I2
Analog
Input current, bias voltage approximately GND
3
I3
Analog
Input current, bias voltage approximately GND
4
I4
Analog
Input current, bias voltage approximately GND
5
I5
Analog
Input current, bias voltage approximately GND
6
RFA
Analog
External resistor to GND sets frequency of oscillator A
7
RFB
Analog
External resistor to GND sets frequency of oscillator B
8
NE2
Digital
Digital control of channel 2 (low active)
9
NE3
Digital
Digital control of channel 3 (low active)
10
NE4
Digital
Digital control of channel 4 (low active)
11
NE5
Digital
Digital control of channel 5 (low active)
12
ENABLE
Digital
Enables output current (high active)
13
VCC2
Supply
+5 V power supply for IOUT
14
ENOSC
Digital
Enables RF oscillator (high active)
15
SELA
Digital
High: selects IOUTA, RFA, RSA
Low: selects IOUTB, RFB, RSB
16/17
IOUTB
Analog
Output current source B for laser diode
18
RSB
Analog
External resistor to GND sets swing of oscillator B
19
RSA
Analog
External resistor to GND sets swing of oscillator A
20
GND
Supply
Ground
21/22
IOUTA
Analog
Output current source A for laser diode
23
VCC2
Supply
+5 V power supply for IOUT
24
VCC1
Supply
+5 V power supply for circuit
3
4503DDVD02/05
T0800
Figure 2-2.
Pinning
QFN28
I4
I5
RFA
RFB
GND
NE2
NE3
IOUTA
IOUTA
GND
RSA
RSB
IOUTB
IOUTB
I3
I2
IR
NC
V
CC1
V
CC2
V
CC2
NE
4
NE
5
EN
ABL
E
V
CC2
V
CC2
EN
O
S
C
SEL
A
28 27 26 25 24 23 22
8 9 10 11 12 13 14
1
2
3
4
5
6
7
21
20
19
18
17
16
15
Table 2-2.
Pin Description: QFN28
Pin
Symbol
Type
Function
1
I4
Analog
Input current, bias voltage approximately GND
2
I5
Analog
Input current, bias voltage approximately GND
3
RFA
Analog
External resistor to GND sets frequency of oscillator A
4
RFB
Analog
External resistor to GND sets frequency of oscillator B
5
GND
Supply
Ground
6
NE2
Digital
Digital control of channel 2 (low active)
7
NE3
Digital
Digital control of channel 3 (low active)
8
NE4
Digital
Digital control of channel 4 (low active)
9
NE5
Digital
Digital control of channel 5 (low active)
10
ENABLE
Digital
Enables output current (high active)
11, 12
VCC2
Supply
+5 V power supply IOUT
13
ENOSC
Digital
Enables RF oscillator (high active)
14
SELA
Digital
High: selects IOUTA, RFA, RSA
Low: selects IOUTB, RFB, RSB
15
IOUTB
Analog
Output current source B for laser diode
16
IOUTB
Analog
Output current source B for laser diode
17
RSB
Analog
External resistor to GND sets swing of oscillator B
18
RSA
Analog
External resistor to GND sets swing of oscillator A
19
GND
Supply
Ground
20
IOUTA
Analog
Output current source A for laser diode
21
IOUTA
Analog
Output current source A for laser diode
22, 23
VCC2
Supply
+5 V power supply IOUT
24
VCC1
Supply
+5 V power supply circuit
25
NC
Not connected
26
IR
Analog
Input current, bias voltage approximately GND
27
I2
Analog
Input current, bias voltage approximately GND
28
I3
Analog
Input current, bias voltage approximately GND
Paddle
Should be connected with ground
4
4503DDVD02/05
T0800
Figure 2-3.
Block Diagram
Channel 3
Channel 2
I3
NE3
I2
NE2
Read channel
RF oscillator
IR
ENOSC
ENABLE
RFA
RSA
Channel 4
Channel 5
I4
NE4
NE5
I5
IOUTA
IOUTB
RFB
RSB
SELA
5
4503DDVD02/05
T0800
3.
Absolute Maximum Ratings
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameter
Symbol
Value
Unit
Supply voltage
V
CC
-0.5 to +6.0
V
Input voltage at IR, I2, I3, I4, I5
V
IN1
-0.5 to +0.5
V
Input voltage at NE2, NE3, NE4, NE5, ENOSC
V
IN2
-0.5 to V
CC
+0.5
V
Output voltage
V
OUT
-0.5 to V
CC
-1
V
Power dissipation
P
tot
0.7
(1)
to 1
(2)
W
Junction temperature
T
J
150
C
Storage temperature range
T
stg
-65 to +125
C
Notes:
1. R
thJA
115 K/W, T
amb
= 70C
2. R
thJA
115 K/W, T
amb
= 25C
4.
Thermal Resistance
Parameter
Symbol
Value
(1)
Unit
Junction ambient
R
thJA
115 (SSO24)
35 (QFN28)
K/W
K/W
Note:
1. Measured with multi-layer test board (JEDEC standard JESD51-7)
5.
Recommended Operating Conditions
Parameter
Symbol
Value
Unit
Supply voltage range
V
CC
4.5 to 5.5
V
Input current
I
IR
, I
I2
, I
I3
, I
I4
, I
I5
< 2.5
mA
External resistor to GND to set oscillator
frequency
RFA, RFB
> 3
k
External resistor to GND to set oscillator swing
RSA, RSB
> 100
Operating temperature range
T
amb
0 to +70
C