SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
The SM16705P/F/FN are specifically designed for
LED display constant current drivers.
This constant current output circuits is able to setup
by external resistor (I
OUT
= 5 ~ 90mA).
This IC is monolithic integrated circuit designed to be
used together with Bi-CMOS process.
The devices consist of 8bit shift register, latch, AND-
GATE and Constant Current Drivers.
PIN ASSIGNMENTS
GENERAL DESCRIPTION
FEATURES
Page 1
* Constant Current Output :
can setup all output current with one resistor
for 5 to 90mA.
* Maximum Clock Frequency :
f
CLK
= 25 (MHz)
(Cascade Connect Operate,
Topr = 25
o
C)
* 5V CMOS Compatible Input
* 16 pin DIP, SOP or SSOP package
* Constant Output Current Matching :
Output-GND
Voltage
Current
Matching
Output Current
0.7V
6.0%
5 ~ 90mA
0.4V
6.0%
5 ~ 40mA
V.2.0 MAY,2003
SM16705
16
9
10
11
12
13
14
15
1
8
7
6
5
4
3
2
GND
OUT3
OUT2
OUT1
OUT0
LATCH
CLOCK
SERIAL-IN
OUT4
V
DD
OUT5
OUT6
OUT7
ENABLE
SERIAL-OUT
R-EXT
Part Number
Package Type
SM16705F
16pin SOP
SM16705P
16pin DIP
SM16705FN
16pin SSOP
Page 2
V.2.0 MAY,2003
PIN DESCRIPTION
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Pin NO.
1
2
3
4
5~12
14
13
15
16
I / O
I
I
I
O
O
I
I / O
Pin Name
GND
SERIAL-IN
CLOCK
LATCH
OUT0~7
SERIAL-OUT
ENABLE
R-EXT
VDD
GND terminal
Function Description
Terminal of serial-data input to the shift register.
Input terminal of a clock for shift register on rising edge.
Input terminal of data strobe. Latches pass data with
"H" level input of LATCH-terminal, and hold data with
"L" level input.
Current-sinking output terminals.
Output terminal of serial-data for next SERIAL-IN terminal.
Input terminal of output enable. All outputs (OUT0~7) do
off with "H" level input of ENABLE-terminal and do on
with "L" level input.
An external resistor at this terminal establishes all of the
output current.
5V supply voltage terminal.
TRUTH TABLE
EQUIVALENT CIRCUIT OF INPUTS AND OUTPUTS
Page 3
D
n
... D
n - 5
... D
n - 7
No change
D
n
D
n + 1
D
n - 7
D
n
- 6
UP
UP
H
L
L
L
D
n + 2
... D
n
- 3
... D
n - 5
D
n + 2
D
n - 5
UP
H
L
D
n + 2
... D
n
- 3
... D
n
- 5
D
n + 3
D
n - 5
DOWN
X
L
Off
D
n + 3
D
n - 5
DOWN
X
H
V
DD
ENABLE
GND
R
IN
(Up)
V
DD
LATCH
GND
R
IN
(Down)
1. ENABLE terminal
2. LATCH terminal
3. CLOCK, SERIAL-IN terminal
4. SERIAL-OUT terminal
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
V.2.0 MAY,2003
Note : 1.OUT0~7=on when Dn="H" ; OUT0~7=off when Dn="L".
2. In order to ensure that the level of the power supply voltage is correct, an external resistor
must be connected betwen R-EXT and GND.
V
DD
CLOCK,
SERIAL-IN
GND
V
DD
GND
SERIAL-OUT
OUT0 ... OUT5 ... OUT7
SERIAL-IN
SERIAL-OUT
CLOCK
LATCH
ENABLE
BLOCK DIAGRAM
TIMING DIAGRAM
Note : Latches are level sensitive, not rising edges sensitive and not synchronous CLOCK.
Input of LATCH-terminal to H Level, data passes latches, and input of LATCH -terminal to L level, data
hold latches.
Input of ENABLE-terminal to H Level, all output (OUT0 ~ 7) do off.
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
V.2.0 MAY,2003
Page 4
R-EXT
ENABLE
LATCH
SERIAL-IN
CLOCK
SERIAL-
OUT
I-REG.
OUT0
OUT1
OUT7
Q
ST D
Q
ST D
Q
ST D
D Q
CK
D Q
CK
D Q
CK
CLOCK
SERIAL-IN
LATCH
ENABLE
OUT0
OUT1
OUT2
OUT7
SERIAL-OUT
0V
5V
0V
0V
5V
0V
5V
Off
On
Off
5V
Off
Off
On
0V
5V
.....
On
On
MAXIMUM RATINGS (Ta = 25
o
C)
Page 5
DIP : Ambient temperature derated above 25
o
C in the proportion of 11.8mW /
o
C
SOP/ SSOP: Ambient temperature delated above 25
o
C in the proportion of 6.3mW /
o
C
(Note)
RECOMMENDED OPERATING CONDITION (Ta = -40 ~ 85
o
C unless otherwise noted)
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
V2.0 MAY,2003
P
D
V
DD
V
IN
I
OUT
V
OUT
f
CLK
I
GND
Topr
Tstg
Rth (j-a)
Supply Voltage
Input Voltage
Output Current
Output Voltage
Clock Frequency
GND Terminal Current
Operating Termerature
Storage Temperature
Thermal Resistance
Power Dissipation
0 ~ 7.0
- 0.4 ~ VDD +0.4
90
- 0.5 ~ 20.0
25
720
1.47 (DIP : FREE AIR, Ta = 25
o
C)
0.78 (SOP/ SSOP : ON PCB, Ta = 25
o
C)
-40 ~ 85
-55 ~ 150
85 (DIP : FREE AIR, Ta = 25
o
C)
160 (SOP/ SSOP : ON PCB, Ta = 25
o
C)
V
V
mA
V
MHz
mA
W
o
C / W
o
C
o
C
Symbol
Characteristic
Rating
Unit
V
Output Current
Supply Voltage
Output Voltage
mA
V
V
5
4.5
5.0
88
1.0
5.5
15.0
OUTn,DC test circuit
SERIAL-OUT
I
O
I
OH
V
DD
V
OUT
-1.0
SERIAL-OUT
I
OL
Input Voltage
V
DD
= 4.5 ~ 5.5V
0.7
V
DD
V
DD
+0.3
V
IH
LATCH Pulse Width
CLOCK Pulse Width
ns
ns
20
20
tw LAT
tw CLK
ns
2000
tw EN
ENABLE Pulse Width
Hold Time for DATA
Set-up Time for LATCH
ns
ns
20
20
t
hold
(D)
t
setup
(L)
ns
20
t
setup
(D)
Set-up Time for DATA
Characteristic
Unit
Min.
Typ. Max.
Condition
Symbol
-0.3
0.3
V
DD
V
IL
W
0.40
Ta = 85
o
C
(SOP/ SSOP ON PCB)
MHz
25
Clock Frequency
Cascade operation
f
CLK
Power Dissipation
P
D
Ta = 85
o
C(DIP FREE AIR)
0.82
ELECTRICAL CHARACTERISTICS (V
DD
= 5.0V, Ta = 25
o
C unless otherwise noted)
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 6
V2.0 MAY,2003
Supply Voltage Regulation
% / V
DD
Symbol
V
IH
V
IL
V
OL
V
OH
I
OL1
I
OL2
R
IN
(up)
R
IN
(down)
I
DD
(off) 1
I
DD
(off) 2
I
DD
(off) 3
I
DD
(on) 1
V
DD
(on) 2
I
OH
Characteristic
Input
Voltage
"H" Level
"L" Level
Output
Voltage
SERIAL-OUT
Output Current 1
Current Skew
Output Current 2
Current Skew
Pull-Up Resistor
Pull-Down Resistor
Supply
Current
"OFF"
"ON"
Output Leakage Current
I
OL1
I
OL3
Condition
Min.
Typ.
Max.
Unit
V
0.7
V
DD
GND
V
DD
0.3
V
DD
I
OL
= 1.0mA
V
0.4
4.6
I
OH
= -1.0mA
mA
REXT = 470
(Include skew)
1.5
4.0
I
OUT
= 40mA
V
CE
= 0.4V
%
REXT = 470
mA
REXT = 240
1.5
4.0
I
OUT
= 75mA
V
CE
= 0.7V
%
REXT = 240
150
300
600
K
100
200
400
K
R
EXT
=OPEN, OUT0 ~ 7 = off
0.6
1.2
mA
R
EXT
=470, OUT0 ~ 7 = off
3.5
5.0
8.0
R
EXT
=240, OUT0 ~ 7 = off
6.5
8.0
15.0
R
EXT
=470, OUT0 ~ 7 = on
7.0
8.0
18.0
R
EXT
=240, OUT0 ~ 7 = on
10.0
15.0
32.0
REXT = 470, Ta = -40 ~ 85
o
C
2.5
5.0
% / V
V
OH
= 15.0V
10
A
V
CE
= 0.7V
V
CE
= 0.7V
I
OL2
34.1
40.0
45.9
33.7
39.5
45.3
66.3
78.0
89.7
V
CE
= 0.4V
SWITCHING CHARACTERISTICS (Ta = 25
o
C unless otherwise noted)
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 7
V2.0 MAY,2003
Characteristic
Propagation
Delay Time
("L" to "H")
Propagation
Delay Time
("H" to "L")
Symbol
tpLH
tpHL
Unit
ns
ns
Min.
Typ.
Max.
400
800
20
40
400
400
800
800
200
400
20
40
200
200
400
400
Condition
V
DD
= 5.0V
R
EXT
= 470
V
L
= 3.0V
R
L
= 62
C
L
= 10 pF
Output Rise Time
Output Fall Time
tor
tof
ns
150
150
300
300
600
600
SERIAL-IN-OUTn
LATCH-OUTn
SERIAL-IN-OUTn
LATCH-OUTn
ENABLE-OUTn
CLOCK
-SERIAL-OUT
ENABLE-OUTn
CLOCK
-SERIAL-OUT
TEST CIRCUIT
DC Characteristic
AC Characteristic
Utmost care is necessary in the design of the output line, V
DD
and GND line, since IC may be destroyed due
to short-circuit between outputs, air contamination fault, or fault by improper grounding.
PRECAUTIONS FOR USING
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
R-EXT
GND
SERIAL-OUT
OUT0
SERIAL-IN
LATCH
CLOCK
ENABLE
OUT7
I
OL
I
DD
V
IL
,VI
H
I
IL,
II
H
V
DD
lref
R-EXT GND
OUT0
SERIAL-IN
LATCH
CLOCK
ENABLE
OUT7
SW-
MATRIX
V
IL,
V
IH
SERIAL-OUT
C
L
V
L
R
L
V
DD
C
L
Page 8
V2.0 MAY,2003
TIMING WAVEFORM
1. CLOCK, SERIAL-IN, SERIAL-OUT, OUTn
90%
50%
10%
90%
50%
10%
90%
50%
10%
90%
50%
10%
t
pLH
t
pHL
t
setup
(D)
t
hold
(D)
tr
tf
tw CLK
50%
50%
50%
CLOCK
SERIAL-IN
SERIAL-OUT,
OUTn (current)
t
or
t
of
tw CLK
2. CLOCK-LATCH
3. ENABLE-OUTn
Page 9
V2.0 MAY,2003
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
50%
50%
"L" level = DATA HOLD
t
s
etup
(L)
50%
CLOCK
SERIAL-IN
LATCH
t
pLH
t
pHL
50%
50%
50%
50%
ENABLE
OUTn (Current)
50%
t
W
LAT
t
W
EN
Output Current - Duty (LED turn-on rate)
R
EXT
- I
OUT
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Ta - P
D
Ambient Temerature Ta (
o
C)
Power dissipation P
D
(W/I
C
)
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
-40 -20
0
20
40
60
80
F/FN FREE AIR
F/FN ON PCB
P FREE AIR
Page 10
V2.0 MAY,2003
I
OUT
( mA )
R
EXT
()
Fig. 1
100
90
70
80
60
50
30
40
10
20
0
200 300
500
1,000
2,000 3,000 5,000
V
OUT
= 0.7V
V
DD
= 5.0V
I
OUT
{(1.25 / R
EXT
()} 14.7
Output Current - R
EXT
Resistor
Output Current - Output Voltage
Ice
Vce-Ice
R=240
R=470
R=3900
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
-0.01
0
0.5
1
1.5
2
2.5
3
3.5
Vce
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 11
V.2.0 MAY,2003
[1] Output Current (I
OUT
)
[2] Total supply voltage (V
LED
)
I
OUT
is set by the enternal resistor (R-EXT) as shown in Firgure1.
This device can operate at 0.4~0.7V (V
OUT
). When a higher voltage is input to the device, the excess
voltage is consumed inside the device, that leads to more power dissipation.
In order to minimize power dissipation and loss, we would like to recommend to set the total supply voltage
as shown below,
V
LED
(total supply voltage)=V
OUT
(IC Supply Voltage)+ Vf (LED Forward voltage)
+ VDS (MOSFET Voltage Drop)
When the total supply is too high considering the power dissipation of this device, an additional R can
decrease the supply voltage (V
OUT
).
[3] Pattern Layout
This device has only one ground pin that means signal ground pin and power ground pin are common.
If ground pattern layout contains large inductance and impedance, and the voltage between ground
and LATCH, CLOCK terminals exceeds 2.5V by switching noise during operation, this device may miss-
operate. So we would advise you to pay attention to pattern layout to minimize ground inductance.
PATTERN LAYOUT
V
LED
= 3 ~ 4 (V)
R-EXT
SERIAL-IN
LATCH
CLOCK
ENABLE
OUT0
OUT7
SERIAL-OUT
R-EXT
SERIAL-IN
LATCH
CLOCK
ENABLE
OUT7
GND
SERIAL-OUT
CPU
GND
V
DD
OUT0
SCAN
SDM4953
SDM9435A
VDS
V
DD
V
DD
V
DD
V
DD
V
OUT
V
OUT
V
f
V
f
SDM4952
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 12
V.2.0 MAY,2003
SM16705P 16 PIN DIP
PACKAGE OUTLINE
9.02 +
0.508
0 ~ 15
7.62
8
1
6.35 +
0.13
16
9
Unit : mm
Weight: 1.11g(Type)
19.69 MAX
19.18 + 0.51
0.635 + 0.254
2.54
1.524
0.4572
5.33MAX
3.3 +
0.1
0.38MIN
3.3 +
0.508
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 13
V.2.0 MAY,2003
PACKAGE OUTLINE
SM16705F 16 PIN SOP
Unit : mm
16
9
8
1
0.56
1.27
0.51
4.0MAX
6.2MAX
10
1.75
1.5
0.25
0.25
1.27
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Page 14
V.2.0 MAY,2003
SM16705FN 16 PIN SSOP
PACKAGE OUTLINE
Unit : mm
16
9
8
0.635
0.3MAX
1
3.91
5.99
0.229
1.63MAX
1.5
0.15
4.9
0.254
0.635
PDF 
ZIP