Macroblock
Datasheet
MBI5170
8-Bit Constant Current LED Sink Driver
with Gain Control
Features
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Compatible with MBI5168 in package and electrical characteristics
Exploit
Share-I-O™
technique to provide two operation modes:
Normal Mode with the same functionality as MB5168,
Current Adjust Mode to program output current gain
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8 constant-current output channels
Output current adjustable through an external resistor
Constant output current range: 5 -120 mA
Excellent output current accuracy,
between channels <
±3%
(max.), and
between ICs <
±6%
(max.).
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Constant output current invariant to load voltage change
Fast response of output current,
OE (min.): 200 ns @I
out
< 60mA
OE (min.): 400 ns @I
out
= 60~100mA
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25MHz clock frequency
Schmitt trigger input
3.3V~ 5V supply voltage
256-step run-time programmable output current gain
suitable for white balance application
MBI5170CDW
MBI5168CDW
SOP16-150-1.27 Weight：0.13g
P-DIP16-300-2.54 Weight：1.02g
M B
MBI5168CN
N
I5 0 0 1
MBI5170CN
C
MBI5001CN
MBI5001CD
MBI5170CD
MBI5168CD
MBI5001CD
SOP16-300-1.27 Weight：0.37g
MBI5168CP
MBI5170CP
Current Accuracy
Between Channels
<
±3%
Between ICs
<
±6%
Conditions
I
OUT
= 10 ~ 100 mA,
V
DS
= 0.8V, V
DD
= 5.0V
SSOP16-150-0.64 Weight：0.07g
©Macroblock,
Inc. 2004
Floor 6-4, No.18, Pu-Ting Rd., Hsinchu, Taiwan 30077, ROC.
TEL: +886-3-579-0068, FAX: +886-3-579-7534, E-mail:
info@mblock.com.tw
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August 2004, VA.00
MBI5170
8-Bit Constant Current LED Sink Driver with Gain Control
Product Description
MBI5170 succeeds MBI5168 and also exploits
PrecisionDrive™
technology to enhance its output characteristics.
Furthermore, MBI5170 uses the idea of
Share-I-O™
technique to make MBI5170 backward compatible with
MBI5168 in both package and electrical characteristics and extend its functionality for run-time LED current gain
control in LED display systems.
MBI5170 contains an 8-bit Shift Register and an 8-bit Output Latch, which convert serial input data into parallel
output format. At MBI5170 output stages, eight regulated current ports are designed to provide uniform and
constant current sinks with small skew between ports for driving LED’s with a wide range of forward voltage (Vf)
variations. Users may adjust the output current from 5 mA to 120 mA with an external resistor R
ext
, which gives
users flexibility in controlling the light intensity of LED’s. MBI5170 guarantees to endure maximum 17V at the
output ports. Besides, the high clock frequency up to 25 MHz also satisfies the system requirements of high
volume data transmission.
By means of the
Share-I-O™
technique, MBI5170 adds new functionality on the pins LE and
OE
of MBI5168 to
provide an additional function, Current Gain Control, without any extra pins. Thus, MBI5170 could be a drop-in
replacement of MBI5168. The printed circuit board originally designed for MBI5168 may be also applied to
MBI5170. In MBI5170 there are two operation modes and three phases: Normal Mode phase, Mode Switching
transition phase, and Current Adjust Mode phase. The signal on the multi-function pin
OE
/SW would be monitored.
Once a one-clock-wide short pulse appears on the pin
OE
/SW, MBI5170 would enter the Mode Switching phase.
At this moment, the voltage level on the pin LE/MOD/CA is used for determining the next mode to which MBI5170
is going to switch.
In the Normal Mode phase, MBI5170 has similar functionality to MBI5168. The serial data could be transferred into
MBI5170 via the pin SDI, shifted in the Shift Register, and go out via the pin SDO. The LE/MOD/CA can latch the
serial data in the Shift Register to the Output Latch.
OE
/SW would enable the output drivers to sink current.
On the other hand, the Current Adjust Mode phase allows users to adjust the output current level by setting a
run-time programmable Configuration Code. The code is sent into MBI5170 via the pin SDI. The positive pulse of
LE/MOD/CA would latch the code in the Shift Register into a built-in 8-bit Configuration Latch, instead of the Output
Latch. The code would affect the voltage at the terminal R-EXT and control the output current regulator. The output
current could be adjusted finely by a current gain ranging from (1/12) to (127/128) in 256 steps. Hence, the current
skew between IC’s can be compensated within less than 1% and this feature is suitable for white balancing in LED
color display panels.
Pin Assignment
GND
SDI
CLK
LE/MOD/CA
OUT 0
OUT1
OUT2
OUT3
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VDD
R-EXT
SDO
OE/SW
OUT7
OUT6
OUT5
OUT4
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August 2004, VA.00
MBI5170
8-Bit Constant Current LED Sink Driver with Gain Control
Terminal Description
Pin No.
1
2
3
Pin Name
GND
SDI
CLK
Function
Ground terminal for control logic and current sinks
Serial-data input to the Shift Register
Clock input terminal for data shift on rising edge
Output channel data strobe input terminal:
in the Normal Mode phase, serial
data in the Shift Register is transferred to the respective Output Latch when
LE/MOD/CA is high; the data is latched inside the Output Latch when
LE/MOD/CA goes low. If the data in the Output Latch is
“1”
(High), the
respective output channel will be enabled after OE /SW is pulled down to low.
Mode selection input terminal:
in the Mode Switching phase, LE/MOD/CA
couldn’t strobe serial data but its level is used for determining the next mode to
which MBI5170 is going to switch. When LE/MOD/CA is high, the next mode is
the Current Adjust Mode; when low, the next mode is the Normal Mode.
Configuration data strobe input terminal:
in the Current Adjust Mode phase,
serial data is latched into the Configuration Latch, instead of the Output Latch in
the Normal Mode. The serial data here is regarded as the Configuration Code,
which affect the output current level of all channels.
(See
Operation Principle)
Output enable terminal:
no matter in what phase MBI5170 operates, the
signal OE /SW can always enable output drivers to sink current. When its level
is (active) low, the output drivers are enabled; when high, all output drivers are
turned OFF (blanked).
Mode switching trigger terminal:
a one-clock-wide short signal pulse of
OE /SW could put MBI5170 into the Mode Switching phase.
(See
Operation Principle)
Serial-data output to the following SDI of next driver IC
Input terminal used to connect an external resister for setting up all output
current
Supply voltage terminal
4
LE/MOD/CA
5-12
OUT0 ~ OUT7 Constant current output terminals
13
OE /SW
14
15
16
SDO
R-EXT
VDD
In MBI5170, the relationship between the functions of pin 4 and 13 and the operation phases is listed below:
Pin No.
Pin Name
Function
LE: latching serial data into the Output Latch
4
LE/MOD/CA
MOD: mode selection
CA: latching serial data into the Configuration Latch
13
OE /SW
OE : enabling the current output drivers
SW: entering the Mode Switching phase
Normal
Mode
Yes
No
No
Yes
Yes
Mode
Switching
No
Yes
No
Yes
Yes
Current
Adjust
Mode
No
No
Yes
Yes
Yes
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August 2004, VA.00
MBI5170
8-Bit Constant Current LED Sink Driver with Gain Control
Block Diagram
OUT0
OUT
1
OUT6
OUT7
R-EXT
VDD
I
OUT
Regulator
OE /SW
Control Logic
LE/MOD/CA
GND
8-Bit Output Driver
8
8
8-Bit Output Latch
8
SDO
8-Bit Configuration Latch
CLK
8
8-Bit Shift Register
SDI
Equivalent Circuits of Inputs and Outputs
OE /SW Terminal
VDD
LE/MOD/CA Terminal
VDD
OE /SW
LE/MOD/CA
CLK, SDI Terminal
VDD
SDO Terminal
VDD
CLK, SDI
SDO
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August 2004, VA.00
MBI5170
8-Bit Constant Current LED Sink Driver with Gain Control
Timing Diagram
Normal Mode
N= 0
1
2
3
4
5
6
7
CLK
SDI
LE/MOD/CA
OE /SW
OFF
ON
OFF
ON
OUT0
OUT1
OUT2
OFF
ON
OFF
OUT3
ON
OFF
OUT6
ON
OFF
OUT7
ON
SDO
:
don’t care
Truth Table (In Normal Mode)
CLK
LE/MOD/CA
H
L
H
X
X
OE /SW
L
L
L
L
H
SDI
D
n
D
n+1
D
n+2
D
n+3
D
n+3
OUT0
…
OUT5
…
OUT 7
D
n
…..
D
n - 5
….
D
n - 7
No Change
D
n + 2
….
D
n - 3
….
D
n - 5
D
n + 2
….
D
n - 3
….
D
n - 5
Off
SDO
D
n-7
D
n-6
D
n-5
D
n-5
D
n-5
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August 2004, VA.00
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