Datasheet
Laser Driver for Projectors
MAX3600
12
Video Input Buffers
The synchronous video data inputs (D0 to D9, SYNC,
CLK, and PO) are pseudo-differential. Each input is com-
pared to V
REF
, as shown in Figure 6.
D0 to D9, PO, and SYNC can be left open. SYNC can
be connected to REF if not used (for reduced power
consumption).
Video Demultiplexer
The video demultiplexer (Figure 7) can accommo-
date configurations as shown in the Typical Operating
Circuits. In Configuration 1 (Figure 19), 10-bit red, green,
and blue video data is time multiplexed. The SYNC sig-
nal is used to demultiplex the video data.
In Configuration 2 (Figure 21), each output driver uses
VIDEO2 as a data source.
Driver Outputs
The driver outputs provide currents to the lasers as
shown in Figure 8.
The transfer characteristic of the driver outputs is shown
in Figure 10 and Equation 1.
Equation 1:
HIGH HIGH
OUT LOW LOW
G gs OS os
VIDEO
I G OS
3FFh FFh FFh
××
−= + + +
where:
• Current into the laser driver is positive (out is negative)
• VIDEO is the 10-bit video input
• gs is the 8-bit gain setting register
• os is the 8-bit offset setting register
• G
LOW
is the minimum gain (mA)
• (G
LOW
+ G
HIGH
) is the maximum gain (mA)
• OS
HIGH
is the maximum offset (mA)
• OS
LOW
is the minimum offset (mA)
The output compliance voltage (V
C_
= V
A_
- V
OUT_
,
Figure 9) defines the output voltage required to obtain
low overshoot and fast settling time.
Table 2 summarizes the typical output current capability
for each driver output. Table 3 summarizes the maximum
ratings for each driver output.
Figure 6. Video Inputs
Table 2. Driver Output Typical Parameter
Summary
Table 3. Driver Output Absolute
Maximum Ratings (Current Out of Part)
V
DDQ
VIDEO DATA
(LVCMOS)
R
TT
R
T
2R
TT
R
TT
REF
V
DDQ
/2
D0–D9,
CLK, PO,
SYNC
VIDEO BUFFER
VIDEO
PROCESSOR
MAX3600
MAX3600A
MAX3600R
MAX3600G
MAX3600B
PARAMETER
OUT1
(mA)
OUT2
(mA)
OUT3
(mA)
OUT4
(mA)
Minimum Gain (G
LOW
) 12 40 10 10
Maximum Gain
(G
LOW
+ G
HIGH
)
227 690 170 185
Maximum Offset
(OS
HIGH
)
83 83 83 155
PARAMETER
OUT1
(mA)
OUT2
(mA)
OUT3
(mA)
OUT4
(mA)
DC Current
(T
J
= +125NC)
320 735 245 310
DC Current
(T
J
= +110NC)
480 1100 382 465
Peak Current
(t < 1Fs, T
J
= +125NC)
640 1470 490 620