LMH6533
Four Channel Laser Diode Driver with Dual Output,
LVDS Interface and HFM Oscillator
General Description
The LMH
TM
6533 is a laser diode driver for use in combina-
tion DVD/CD recordable and rewritable systems. The part
contains two high-current outputs for reading and writing the
DVD (650 nm) and CD (780 nm) lasers. Functionality in-
cludes read, write and erase through four separate switched
current channels. The channel currents are summed to-
gether at the selected output to generate multilevel wave-
forms for reading, writing and erasing of optical discs. The
LVDS interface delivers DVD write speeds of 12x and higher
while minimizing noise and crosstalk. The LMH6533 is opti-
mized for both speed and power consumption to meet the
demands of next generation systems. The part features a
150 mA read channel plus one 300 mA and two 150 mA write
channels, which can be summed to allow a total output
current of 500 mA or greater. The channel currents are set
through four independent current inputs.
The part is manufactured in National Semiconductor's
VIP10
TM
process, which features bonded wafer technology
and trench isolation for very high switching speeds at low
power levels. An on-board High-Frequency Modulator (HFM)
oscillator helps reduce low-frequency noise of the laser and
is enabled with the ENOSC pin. The fully differential oscilla-
tor circuit minimizes supply line noise, easing FCC approval
of the overall system. The SELB pin (active HIGH) selects
the output channel and oscillator settings. External resistors
determine oscillator frequency and amplitude for each set-
ting. The write and erase channels can be switched on and
off through dedicated LVDS interface pins.
Features
n
Fast switching: Rise and fall times
<
0.8 ns
n
Low voltage differential signaling (LVDS) channels
enable interface for the fast switching lines
n
Low output current noise:
<
0.5nA/
n
Dual output: Selectable by SELB pin (active HIGH)
n
Four independent current channels
-- Gain of 300, 300 mA write channel
-- Gain of 150, 150 mA low-noise read channel
-- Two gain of 150, 150 mA write channels
-- 500 mA minimum combined output current
n
Integrated AC Coupled HFM Oscillator
-- Selectable frequency and amplitude setting by
external resistors
-- 200 MHz to 600 MHz frequency range
-- Amplitude to 100 mA peak-to-peak modulation
n
Complete shutdown by ENABLE pin
n
5V single-supply operation
n
Logic inputs TTL and CMOS compatible
n
Space saving Leadless Leadframe Package LLP
-28
Applications
n
Combination DVD/CD recordable and rewritable drives
n
DVD camcorders
n
DVD video recorders
Block Diagram
20027701
LMH
TM
is a trademark of National Semiconductor Corporation.
VIP10
TM
is a trademark of National Semiconductor Corporation.
LLP
is a registered trademark of National Semiconductor.
May 2004
LMH6533
Four
Channel
Laser
Diode
Driver
with
Dual
Output,
L
VDS
Interface
and
HFM
Oscillator
2004 National Semiconductor Corporation
DS200277
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance
Human Body Model
2KV (Note 2)
Machine Model
200V (Note 3)
Supply Voltage (V
+
V
-
)
5.5V
Differential Input Voltage
5.5V
Output Short Circuit to Ground
(Note 4)
Continuous
Input Common Mode Voltage
V
to V
+
Storage Temperature Range
-65C to +150C
Junction Temperature (Note 5)
+150C
Operating Ratings
(Note 1)
Supply Voltage (V
+
- V
-
)
4.5V
V
S
5.5V
Operating Temp. Range (T
A
)
(Note 8)
-40C
T
A
85C
Thermal Resistance
(Note 5), (Note 8)
LLP Package
JC
3C/W
JA
(no heatsink)
42C/W
JA
(with heatsink) see (Note 9)
30.8C/W
I
INR
/3/4
1.5 mA (max)
I
IN2
1.0 mA (max)
R
FREQ
1000
(min)
R
AMP
300
F
OSC
100-600 MHz
A
OSC
10-100 mA
PP
+5V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, R
L
= 10
. Boldface limits apply at the temperature extremes.
(Note 8)
Symbol
Parameter
Conditions
Min
(Note 7)
Typ
(Note 6)
Max
(Note 7)
Units
LVDS
V
I
Input Voltage Range
|V
GPD
|
<
50 mV
(Note 7), (Note 9), (Note 11)
825
1550
1575
mV
V
IDTH
Input Diff. Threshold
V
GPD
<
50 mV
(Note 7), (Note 9), (Note 11)
100
0
100
mV
V
HYST
Input Diff. Hysteresis
V
IDTHH
V
IDTH1
(Note 7), (Note 9), (Note 11)
25
0
mV
R
IN
Input Diff. Impedance
(Note 7), (Note 9),(Note 11)
80
104
120
I
IN
Input Current
Excluding R
IN
Current V
CM
= 1.25V
5
50
A
Current Channels
R
IN
Input Resistance all Channels
R
IN
to Ground
425
556
675
I
OS
Current Offset
All Channels Off (Note 12)
7.5
4.75
7.5
mA
A
IW
Current Gain
Channel 2 (Note 13)
270
303
330
A/A
A
IR
Current Gain
Channels 3,4 and Read (Note 13)
135
152
165
A/A
I
LIN-R,3,4
Output Current Linearity
500 A
<
L
IN
<
1000 A; R
LOAD
=
10
Channels Read, 3 and 4
3.5
2.5
+3.5
%
I
LIN-2
Output Current Linearity
500 A
<
L
IN
<
1000 A; R
LOAD
=
10
Channels 2
8
5
+8
%
IOUT
W
Output Current
Channel 2 (Note 12)
@
1mA Input
Current
250
263
mA
IOUT
R,3,4
Output Current
Channel 3, 4 and Read (Note 12)
@
1 mA Input Current
135
150
mA
IOUT
TOTAL
Total Output Current
All Channels (Note 14); R
LOAD
= 5
500
mA
V
TLO
TTL Low Voltage
ENR, ENOSC Input (H to L)
1.51
0.8
V
V
ELO
Enable Low Voltage
Enable Input (H to L)
2.41
0.8
V
V
THI
TTL High Voltage
ENR, ENOSC Inputs (L to H )
2.0
1.54
V
V
EHI
Enable High Voltage
Enable Input (L to H)
2.8
2.4
V
I
SPD
Supply Current, Power Down
Enable = Low (Note 12)
0.003
0.5
mA
I
Sr1
Supply Current, Read Mode,
Oscillator Disabled
ENOSC = Low; (Note 12)
I2 = I3 = I4 = I
R
= 125 A
98.5
120
mA
I
Sr2
Supply Current, Read Mode,
Oscillator Enabled
ENOSC = High; (Note 12)
I2 = I3 = I4 = I
R
= 125 A
98.5
120
mA
LMH6533
www.national.com
2
+5V DC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for T
J
= 25C, R
L
= 10
. Boldface limits apply at the temperature extremes.
(Note 8)
Symbol
Parameter
Conditions
Min
(Note 7)
Typ
(Note 6)
Max
(Note 7)
Units
I
Swr
Supply Current, Write Mode
EN2 = EN3 = EN4 = High; (Note 12)
I2 = I3 = I4 = I
R
= 125 A
182.5
210
mA
I
S
Supply Current
All Channels Disable, No Input
Current. SELB = 0; R
AA
, R
AB
, R
FA
,
R
FB
=
45
mA
+5V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for T
J
= 25C, R
L
= 10
. Boldface limits apply at the temperature extremes.
(Note 8)
Symbol
Parameter
Conditions
Min
(Note 7)
Typ
(Note 6)
Max
(Note 7)
Units
t
r
Write Rise Time
I
OUT
= 40 mA (Read) + 40 mA (10%
to 90%) R
LOAD
= 5
0.50
ns
t
f
Write Fall Time
I
OUT
= 40 mA (Read) + 40 mA (90%
to 10%) R
LOAD
= 5
0.76
ns
t
r
Write Rise Time
I
OUT
= 100 mA (Read) + 100 mA
(10% to 90%) R
LOAD
= 5
0.65
ns
t
f
Write Fall Time
I
OUT
= 100 mA (Read) + 100 mA
(90% to 10%) R
LOAD
= 5
0.75
ns
t
r
Write Rise Time
I
OUT
= 150 mA (Read) + 150 mA
(10% to 90%) R
LOAD
= 5
0.78
ns
t
f
Write Fall Time
I
OUT
= 150 mA (Read) + 150 mA
(90% to 10%) R
LOAD
= 5
0.77
ns
OS
Output Current Overshoot
I
OUT
= 40 mA (Read) + 40 mA
16
%
IN
0
Output Current Noise
I
OUT
= 40 mA; R
LOAD
= 50
;
f = 10 MHz; ENOSC = Low
0.47
nA/
t
ON
I
OUT
ON Prop. Delay
Switched on EN2 and EN2B
0.45
ns
t
OFF
I
OUT
OFF Prop. Delay
Switched on EN2 and EN2B
0.40
ns
t
disr
Disable Time, Read Channel
Switch on ENR
1.1
ns
t
enr
Enable Time, Read Channel
Switch on ENR
1.1
ns
t
dis
Disable Time, (Shutdown)
3
s
t
en
Enable Time, (Shutdown)
3
s
BW
C
Channel Bandwidth, 3 dB
I
OUT
= 50 mA, All Channels
2.5
MHz
f
OSC
Oscillator Frequency
R
F
= 3 k
Range 200 MHz to 600 MHz
270
330
390
MHz
T
DO
Disable Time Oscillator
5.2
ns
T
EO
Enable Time Oscillator
5.4
ns
Note 1: "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The table of "Electrical Characteristics" specifies conditions of device operation.
Note 2: For testing purposes, ESD was applied using `Human body model'; 1.5 k
in series with 100 pF
Note 3: Machine Model, 0
in series with 200 pF.
Note 4: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the
maximum allowed junction temperature of 150C
Note 5: The maximum power dissipation is a function of T
J(MAX
,
JA
, and T
A
. The maximum allowable power dissipation at any ambient temperature is PD =
(T
J(MAX)
-T
A
) /
JA
. All numbers apply for packages soldered directly onto a PC board.
Note 6: Typical values represent the most likely parametric norm.
Note 7: All limits are guaranteed by testing or statistical analysis.
Note 8: Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of
the device such that T
J
= T
A
. There is no guarantee of parametric performance as indicated in the electrical tables under conditions of internal self-heating where
T
J
>
T
A
. See Applications section for information on temperature de-rating of this device.
Note 9: V
GPD
= ground potential difference voltage between driver and receiver
LMH6533
www.national.com
3
Note 10: This figure is taken from a thermal modeling result. The test board is a 4 layer FR-4 board measuring 101 mm x 101 mm x 1.6 mm with a 3 x 3 array of
thermal vias. The ground plane on the board is 50 mm x 50 mm. Ambient temperature in simulation is 22C, still air. Power dissipation is 1W.
Note 11: Reference IEEE Reduced Range Link (RRL) specifications.
Note 12: Positive current corresponds to current flowing into the device.
Note 13: Input currents are set to 0.3 mA
Note 14: Total input current is 4.4 mA (all 4 channels equal) and output currents are summed together (see typical performance characteristics).
Connection Diagram
28-Pin LLP
20027702
Top View
Ordering Information
Package
Part Number
Package Marking
Transport Media
NSC Drawing
28-Pin LLP
LMH6533SP NOPB
LMH6533SP
1k Units Tape and Reel
SPA28A
LMH6533SPX NOPB
4.5k Units Tape and Reel
LMH6533
www.national.com
4
Pin Description
Pin #
Description
Remark
1
Laser driver output channel A
2
Internal Oscillator Enable pin
Oscillator activated if pin is high
3
Temp Sensing Diode
See application note on using this pin
4
Read Channel Enable pin
Read Channel Enabled if pin is high
5
Chip Enable pin
Chip Enabled if pin is high
6
Supply Voltage A
7
Ground Connection A
8
Read Channel current setting
9
Channel 2 current setting
10
Channel 3 current setting
11
Channel 4 current setting
12
Oscillator Frequency setting Channel A
Set by external resistor to ground
13
Oscillator Frequency setting Channel B
Set by external resistor to ground
14
Oscillator Amplitude setting Channel A
Set by external resistor to ground
15
Oscillator Amplitude setting Channel B
Set by external resistor to ground
16
Channel select B
Channel B selected if pin is high
17
LVDS input Channel 2B
Channel 2 active if logical input is low
18
LVDS input Channel 2
Channel 2 active if logical input is high
19
LVDS input Channel 3B
Channel 3 active if logical input is low
20
LVDS input Channel 3
Channel 3 active if logical input is high
21
LVDS input Channel 4B
Channel 4 active if logical input is low
22
LVDS input Channel 4
Channel 4 active if logical input is high
23
NC
24
Supply Voltage
25
Supply Voltage
26
Supply Voltage
27
Laser driver output channel B
28
Ground Connection B
Truth Tables
IOUT CONTROL
Enable
ENR
EN2
EN3
EN4
IOUT
0
X
X
X
X
OFF
1
0
0
0
0
OFF
1
1
0
0
0
A
R
*I
INR
1
1
1
0
0
A
R
*I
INR
+A
2
*I
IN2
1
1
0
1
0
A
R
*I
INR
+A
3
*I
IN3
1
1
0
0
1
A
R
*I
INR
+A
4
*I
IN4
OSCILLATOR CONTROL
Enable
ENOSC
ENR
EN2
EN3
EN4
Oscillator
0
x
x
x
x
x
OFF
1
0
x
x
x
x
OFF
1
1
x
x
x
x
on
LMH6533
www.national.com
5
PDF 
ZIP