SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
GENERAL DESCRIPTION
FEATURES
The SM16705P/F/FN are specifically designed for
LED display constant current drivers.
* Constant Current Output :
can setup all output current with one resistor
for 5 to 90mA.
* Maximum Clock Frequency :
fCLK = 25 (MHz)
(Cascade Connect Operate,
Topr = 25oC)
* 5V CMOS Compatible Input
* 16 pin DIP, SOP or SSOP package
* Constant Output Current Matching :
This constant current output circuits is able to setup
by external resistor (IOUT = 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, ANDGATE and Constant Current Drivers.
Output-GND
Voltage
Current
Matching
Output Current
≧0.4V
± 6.0%
5 ~ 40mA
≧0.7V
± 6.0%
5 ~ 90mA
PIN ASSIGNMENTS
GND
1
16
VDD
SERIAL-IN
2
15
R-EXT
CLOCK
3
14
SERIAL-OUT
LATCH
4
13
ENABLE
OUT0
5
12
OUT7
OUT1
6
11
OUT6
OUT2
7
10
OUT5
OUT3
8
9
OUT4
Part Number
Package Type
SM16705P
16pin DIP
SM16705F
16pin SOP
SM16705FN
16pin SSOP
SM16705
Page 1
V.2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
PIN DESCRIPTION
Pin NO.
I/O
1
Pin Name
GND
Function Description
GND terminal
2
I
SERIAL-IN
3
I
CLOCK
Input terminal of a clock for shift register on rising edge.
4
I
LATCH
Input terminal of data strobe. Latches pass data with
"H" level input of LATCH-terminal, and hold data with
"L" level input.
5~12
O
OUT0~7
Current-sinking output terminals.
13
I
ENABLE
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.
14
O
SERIAL-OUT
15
I/O
R-EXT
16
VDD
Terminal of serial-data input to the shift register.
Output terminal of serial-data for next SERIAL-IN terminal.
An external resistor at this terminal establishes all of the
output current.
5V supply voltage terminal.
Page 2
V.2.0 MAY,2003
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
TRUTH TABLE
OUT0 … OUT5 … OUT7
CLOCK
LATCH
ENABLE
SERIAL-IN
SERIAL-OUT
UP
H
L
Dn
Dn … Dn - 5 … Dn - 7
Dn - 7
UP
L
L
Dn + 1
No change
Dn - 6
UP
H
L
Dn + 2
Dn + 2 … Dn - 3 … Dn - 5
Dn - 5
DOWN
X
L
Dn + 3
Dn + 2 … Dn - 3 … Dn - 5
Dn - 5
DOWN
X
H
Dn + 3
Off
Dn - 5
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.
EQUIVALENT CIRCUIT OF INPUTS AND OUTPUTS
1. ENABLE terminal
2. LATCH terminal
VDD
VDD
RIN(Up)
ENABLE
LATCH
RIN(Down)
GND
3. CLOCK, SERIAL-IN terminal
GND
4. SERIAL-OUT terminal
VDD
VDD
CLOCK,
SERIAL-IN
SERIAL-OUT
GND
GND
Page 3
V.2.0 MAY,2003
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
BLOCK DIAGRAM
OUT0
R-EXT
OUT1
OUT7
I-REG.
ENABLE
Q
Q
Q
ST D
ST D
ST D
LATCH
SERIAL-IN
D Q
D Q
D Q
CK
CK
CK
SERIALOUT
CLOCK
TIMING DIAGRAM
5V
CLOCK
0V
5V
SERIAL-IN
0V
5V
LATCH
0V
5V
ENABLE
0V
On
OUT0
Off
On
OUT1
Off
On
OUT2
Off
.....
On
OUT7
Off
5V
SERIAL-OUT
0V
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.
Page 4
V.2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
MAXIMUM RATINGS (Ta = 25oC)
Characteristic
Symbol
Rating
Unit
Supply Voltage
VDD
0 ~ 7.0
V
Input Voltage
VIN
- 0.4 ~ VDD +0.4
V
Output Current
IOUT
90
mA
Output Voltage
VOUT
- 0.5 ~ 20.0
V
Clock Frequency
fCLK
25
MHz
GND Terminal Current
IGND
720
mA
Power Dissipation
Thermal Resistance
PD
Rth (j-a)
1.47 (DIP : FREE AIR, Ta = 25oC)
W
0.78 (SOP/ SSOP : ON PCB, Ta = 25oC)
85 (DIP : FREE AIR, Ta = 25oC)
oC
160 (SOP/ SSOP : ON PCB, Ta = 25oC)
/W
Operating Termerature
Topr
-40 ~ 85
oC
Storage Temperature
Tstg
-55 ~ 150
oC
(Note)
DIP : Ambient temperature derated above 25oC in the proportion of 11.8mW / oC
SOP/ SSOP: Ambient temperature delated above 25oC in the proportion of 6.3mW / oC
RECOMMENDED OPERATING CONDITION (Ta = -40 ~ 85oC unless otherwise noted)
Characteristic
Supply Voltage
Output Voltage
Output Current
Symbol
VDD
VOUT
IO
IOH
IOL
Condition
Min.
Typ.
Max.
Unit
－
－
4.5
－
5.0
－
－
－
－
5.5
15.0
88
1.0
-1.0
V
V
VDD
+0.3
0.3
VDD
－
－
－
－
－
－
OUTn,DC test circuit
SERIAL-OUT
SERIAL-OUT
5
－
－
VIH
－
0.7
VDD
－
VIL
－
-0.3
－
20
20
2000
20
20
20
－
－
－
－
－
－
－
－
－
－
－
－
Input Voltage
LATCH Pulse Width
CLOCK Pulse Width
ENABLE Pulse Width
Set-up Time for DATA
Hold Time for DATA
Set-up Time for LATCH
Clock Frequency
tw LAT
tw CLK
tw EN
tsetup(D)
thold (D)
tsetup(L)
fCLK
Power Dissipation
PD
VDD = 4.5 ~ 5.5V
Cascade operation
Ta = 85oC(DIP FREE AIR)
Ta = 85oC
(SOP/ SSOP ON PCB)
Page 5
25
0.82
0.40
mA
V
ns
ns
ns
ns
ns
ns
MHz
W
V2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
ELECTRICAL CHARACTERISTICS (VDD = 5.0V, Ta = 25oC unless otherwise noted)
Characteristic
Input
Voltage
Symbol
Condition
Min.
Typ.
Max.
"H" Level
VIH
－
0.7
VDD
－
VDD
"L" Level
VIL
－
GND
－
0.3
VDD
Output Leakage Current
Output
Voltage
Current Skew
Output Current 2
Current Skew
V
IOH
VOH = 15.0V
－
－
10
VOL
IOL = 1.0mA
－
－
0.4
VOH
IOH = -1.0mA
4.6
－
－
IOL1
VCE = 0.7V
34.1
40.0
45.9
IOL2
VCE = 0.4V
REXT = 470Ω
(Include skew)
33.7
39.5
45.3
△ IOL1
IOUT = 40mA
VCE = 0.4V
REXT = 470Ω
－
± 1.5
± 4.0
%
IOL3
VCE = 0.7V
REXT = 240Ω
66.3
78.0
89.7
mA
IOUT = 75mA
VCE = 0.7V
REXT = 240Ω
－
± 1.5
± 4.0
%
REXT = 470Ω, Ta = -40 ~ 85oC
－
2.5
5.0
%/V
SERIAL-OUT
Output Current 1
Unit
μA
V
△ IOL2
mA
Supply Voltage Regulation
% / VDD
Pull-Up Resistor
RIN (up)
－
150
300
600
KΩ
RIN (down)
－
100
200
400
KΩ
Pull-Down Resistor
"OFF"
Supply
Current
IDD (off) 1
REXT =OPEN, OUT0 ~ 7 = off
－
0.6
1.2
IDD (off) 2
REXT =470Ω, OUT0 ~ 7 = off
3.5
5.0
8.0
IDD (off) 3
REXT =240Ω, OUT0 ~ 7 = off
6.5
8.0
15.0
IDD (on) 1
REXT =470Ω, OUT0 ~ 7 = on
7.0
8.0
18.0
VDD (on) 2
REXT =240Ω, OUT0 ~ 7 = on
10.0
15.0
32.0
mA
"ON"
Page 6
V2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
SWITCHING CHARACTERISTICS (Ta = 25 oC unless otherwise noted)
Characteristic
Symbol
Condition
SERIAL-IN-OUTn
Propagation
Delay Time
("L" to "H")
LATCH-OUTn
Typ.
Max. Unit
－
400
800
－
400
800
tpLH
ns
ENABLE-OUTn
－
400
800
CLOCK
-SERIAL-OUT
－
20
40
－
200
400
－
200
400
ENABLE-OUTn
－
200
400
CLOCK
-SERIAL-OUT
－
20
40
150
300
600
VDD = 5.0V
REXT = 470Ω
VL = 3.0V
RL = 62Ω
SERIAL-IN-OUTn
Propagation
Delay Time
("H" to "L")
Min.
LATCH-OUTn
tpHL
Output Rise Time
ns
CL = 10 pF
tor
ns
Output Fall Time
tof
Page 7
150
300
600
V2.0 MAY,2003
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
TEST CIRCUIT
DC Characteristic
IDD
VDD
OUT0
ENABLE
IOL
CLOCK
IIL,IIH
LATCH
VIL,VIH
OUT7
SERIAL-IN
R-EXT
SERIAL-OUT
GND
lref
AC Characteristic
RL
VDD
OUT0
ENABLE
VIL,VIH
SWMATRIX
CL
CLOCK
LATCH
OUT7
SERIAL-IN
SERIAL-OUT
R-EXT GND
CL
VL
PRECAUTIONS FOR USING
Utmost care is necessary in the design of the output line, VDD and GND line, since IC may be destroyed due
to short-circuit between outputs, air contamination fault, or fault by improper grounding.
Page 8
V2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
TIMING WAVEFORM
1. CLOCK, SERIAL-IN, SERIAL-OUT, OUTn
tr
tf
tw CLK
tw CLK
90%
50%
10%
90%
50%
10%
CLOCK
tsetup(D)
50%
thold(D)
50%
50%
SERIAL-IN
tor
tof
90%
50%
10%
90%
50%
10%
SERIAL-OUT,
OUTn (current)
tpLH
tpHL
2. CLOCK-LATCH
50%
50%
CLOCK
SERIAL-IN
"L" level = DATA HOLD
50%
50%
tW LAT
LATCH
tsetup(L)
3. ENABLE-OUTn
tW EN
ENABLE
50%
50%
tpLH
OUTn (Current)
tpHL
50%
Page 9
50%
V2.0 MAY,2003
SM16705P/F/FN
SAMHOP Microelectronics Corp.
8-BIT CONSTANT CURRENT LED DRIVER
Output Current - Duty (LED turn-on rate)
Output Current - REXT Resistor
Ta - PD
REXT - IOUT
100
90
1.4
P FREE AIR
1.2
80
IOUT ( mA )
Power dissipation PD (W/IC)
1.6
1
F/FN ON PCB
0.8
0.6
F/FN FREE AIR
IOUT ≒ {(1.25 / REXT (Ω)} × 14.7
70
60
VOUT = 0.7V
VDD = 5.0V
50
40
30
0.4
20
0.2
0
-40
-20
0
20
40
60
10
0
80
200 300
500
1,000
2,000 3,000 5,000
REXT (Ω)
Ambient Temerature Ta (oC)
Fig. 1
Output Current - Output Voltage
Vce-Ice
0.09
0.08
R=240Ω
0.07
0.06
0.05
R=470Ω
Ice
0.04
0.03
0.02
0.01
R=3900Ω
0
-0.01
0
0.5
1
1.5
2
2.5
3
3.5
Vce
Page 10
V2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
[1] Output Current (IOUT)
IOUT is set by the enternal resistor (R-EXT) as shown in Firgure1.
[2] Total supply voltage (VLED)
This device can operate at 0.4~0.7V (VOUT ). 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,
VLED (total supply voltage)=VOUT (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 (VOUT).
PATTERN LAYOUT
VLED = 3 ~ 4 (V)
VDD
SCAN
SDM4952
SDM4953
VDS SDM9435A
VDD
ENABLE
CLOCK
LATCH
SERIAL-IN
R-EXT
Vf
VDD
OUT0
VOUT
OUT7
GND
SERIAL-OUT
CPU
VDD
ENABLE
CLOCK
LATCH
SERIAL-IN
R-EXT
VDD
Vf
OUT0
VOUT
OUT7
GND
SERIAL-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 missoperate. So we would advise you to pay attention to pattern layout to minimize ground inductance.
Page 11
V.2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
PACKAGE OUTLINE
SM16705P 16 PIN DIP
1
8
7.62
9.02 + 0.508
9
6.35 + 0.13
16
0 ~ 15°
Unit : mm
0.635 + 0.254
2.54
1.524
0.4572
5.33MAX
3.3 + 0.508
19.18 + 0.51
0.38MIN
3.3 + 0.1
19.69 MAX
Weight: 1.11g(Type)
Page 12
V.2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
PACKAGE OUTLINE
SM16705F 16 PIN SOP
Unit : mm
1
8
1.27
0.51
0.25
1.75
10
1.5
0.56
6.2MAX
9
4.0MAX
16
1.27
0.25
Page 13
V.2.0 MAY,2003
SAMHOP Microelectronics Corp.
SM16705P/F/FN
8-BIT CONSTANT CURRENT LED DRIVER
PACKAGE OUTLINE
SM16705FN 16 PIN SSOP
Unit : mm
3.91
8
0.635
0.3MAX
0.254
1.5
4.9
1.63MAX
1
0.229
5.99
9
16
0.635
0.15
Page 14
V.2.0 MAY,2003