AKM AK7864

[AK7864]
AK7864
3 channel LED driver with Charge Pump
Device Outline
This product is include the charge pump power supply and include the 3 channel LED driver who
drives the LED of the anode common in the constant current . The current to pass for each channel
can be adjusted by the external resistance and the register setting. Also, it has the control pins which
turn on or off the current. It is the best for the LED drive for the CIS sensor.
Features
■ Operation Voltage
■ Operating Temperature Range
■ LED driver current
3.3V±5%
0 ~ 70℃
RED: 66mA (Adjustment external resister:22 ~ 66mA)
GREEN: 66mA (Same as above, each channel is spec in
absolute value.)
BLUE: 66mA (Same as above, each channel is spec in
absolute value.)
Usable Vf MAX range of the LED is 4.8V. The resistance for
the current regulation is usable in 1/16W -type.
▪ 50% setting is an upper bound when 3ch becoming
turning on at the same time.
▪
3ch independent ON/OFF.
▪
Current setting in eight steps
When
the
external
resistance
value
becomes
the
assumption outside, it has the protection circuit which
■
■
■
■
Current Accuracy
LED Current rise / fall time
Charge Pump pressor circuit
Package
■ Power
■ Application
MS1152 - E - 01
doesn't make the electric current which flows through the
LED equal to or more than 150mA(-30%~+45%)
±9.1%(by ideal resistance)
10μs (typ.) (10% ~ 90%)
Generate the necessary voltage for the LED (Vf max 4.8V)
16pinQFN 3mm, 0.75mm thickness with radiation TAB in
Solderside
VDD 3.135 ~ 3.465V
A light source driver for CIS module of MFP
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[AK7864]
Block Diagram
CPO
CP1
VDD
CPOUT
(3.3V±5%)
LED_R
LED_G
LED_B
CONT_B
SW
CONT_G
SW
CONT_R
SW
EN
CP
CP(x2)
Current
CC
3bit
CN
8steps
Current R
PDN
Current G
Current B
IREF
VSS
R 1% accuracy
Circuit Block Description
□ Charge Pump Circuit
A necessary voltage for LED (Vf 4.8V or less) lighting is generated from the voltage supplied to VDD
pin. Please supply the generated power supply from CPOUT pin to external LED.
□ LED Driver Part
This product generates has 3 channel LED driver to drive RGB constant current. Use the ON/ OFF
digital terminal to control the constant current.
The current setting can be set to 8 level with CONT_R/G/B and EN combination.
It is possible to light 1ch LED or 3ch simultaneously. Please set the current less than 50% by 3ch
simultaneously.
-
Current setting of 3 channels is same. 3ch ON/OFF independent or at the same time.
Current setting can be set to 8 level with CONT_R/G/B and EN combination.
(100%/87.5%/75%/62.5%/50%/37.5%/25%/12.5%)
When 100%=60mA, 87.5%=52.5mA、75%=45mA、...
When 100%=66mA, 87.5%=57.75mA、75%=49.5mA、...
MS1152 - E - 01
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[AK7864]
Current setting method
The method of setting the LED current is as follows.
Latch the pattern of CONT_R, CONT_G, CONT_B at the time of following EN rise to decide the
current value.After the CONT_R, CONT_G, CONT_B signal fall once, the current interlocks with
CONT_R, CONT_G, CONT_B’s on or off.
The level is set here
EN
Turn RGB on
Not turn on
CONT_R
CONT_G
CONT_B
After fall, LED is on
with EN high period.
The relation between the pattern and the current setting value of CONT_R, CONT_G, CONT_B at
the time of the EN rise as follows.
CONT_R
CONT_G
CONT_B
0
0
0
100%
0
0
1
87.5%
0
1
0
75%
0
1
1
62.5%
1
0
0
50%
1
0
1
37.5%
1
1
0
25%
1
1
1
12.5%
MS1152 - E - 01
Current setting
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2010/09
[AK7864]
Pin Allocation
VSS
9
LED_G 10
VSS 11
LED_R 12
CPOUT 13
VSS 14
AK7864
Top View
CP 15
CN 16
4
LED_B
7
CONT_R
6
CONT_G
5
CONT_B
4 EN
3 PDN
2 IREF
1 VDD
MS1152 - E - 01
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[AK7864]
Pin Functions
No.
1
2
Name
VDD
IREF
3
PDN
I
4
EN
I
5
I
I
LED control input G
I
LED control input R
8
9
10
11
12
13
CONT_
B
CONT_
G
CONT_
R
LED_B
VSS
LED_G
VSS
LED_R
CPOUT
power supply
LED current setting external resister pin
(Use the external resistance Pull Down by power down)
Power down mode terminal
Hi: power up, Lo: power down
LED current enable terminal
Hi:enable, Lo:disable
LED control input B
O
P
O
P
O
O
14
15
VSS
CP
P
I
16
CN
I
LED output pin B ([email protected])
GND
LED output pin G ([email protected])
GND
LED output pin R ([email protected])
Charge pump power supply out put pin
(Use the internal resistance Pull Down by power down)
GND
Charge pump connect with cap positive terminal
(Use the internal resistance Pull Down by power down)
Charge pump connect with cap negative terminal
(Use the internal resistance Pull Down by power down.)
Connect it with GND.
6
7
radiation pad
MS1152 - E - 01
IO
P
O
Description
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2010/09
[AK7864]
Absolute Maximum Ratings
Voltages are referenced to corresponding ground level. VSS=0V
Item
Symbol
Min.
Max.
Unit
Power supply
VDD
−0.3
4.0
V
Input Voltage
VINA
−0.3
VDD+0.3
V
Remarks
Storage temperature
Tstg
−65
150
°C
Operation under a condition exceeding above limits may cause permanent damage to the device.
Normal operation is not guaranteed under the above extreme conditions.
Recommended Operating Conditions
Voltages are referenced to corresponding ground level. VSS=0V
Item
Power supply
Symbol
VDD
Min.
3.135
Ta
0
Storage temperature
Typ.
3.3
Max.
3.465
Unit
V
70
°C
Remarks
When powered-up, Please set PDN to Lo, then set PDN to Hi. Release from reset + PD.
Electrical Characteristics
1. Digital input DC characteristics
Item
H level input
voltage
L level input
voltage
Input
leakage
current
Symbol
VIH
VIL
IL
(VDD=3.135~3.465V, Ta=0∼70°C unless otherwise specified)
Pin
Min.
Typ.
Max.
Unit.
Remarks
Note
0.7×
V
1
VDD
Note
0.3×
V
1
VDD
Note
-2
2
μA
1
(Note 1) PDN, EN, CONT_R,G,B
2.
CP block, Analog characteristics
Item
CPOUT Voltage
CPOUT Rise time
CPOUT Fall time
Current Consumption
MS1152 - E - 01
(VDD=3.135~3.465V, Ta=0∼70°C unless otherwise specified)
Min.
Typ.
Max.
Unit
Remarks
6.27
6.6
6.93
V
@LED current disable
1
msec
20
msec
4.0
mA
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[AK7864]
3.
LEDD block, Analog characteristics
Item
LED drive current range
The LED protection circuit
activation current
LED current
(R/G/B)
LED current accuracy
(R/G/B)
LED current LED pin voltage
dependence
LED Vf
Current Consumption
Min.
22
105
60
86.0
73.5
60.5
48
35.5
23
10.5
-2.5
(VDD=3.135~3.465V ,Ta=0∼70°C unless otherwise specified)
Typ.
Max.
Unit
Remarks
(note 1)
66
mA
150
217.5
mA
66
100
87.5
75
62.5
50
37.5
25
12.5
1.1
72
mA
89.0
76.5
64.5
52
39.5
27
14.5
2.5
%
%
%
%
%
%
%
%
%
4.8
1.1
V
mA
IREF resister =4.7 kΩ±1%
LED pin voltage =(2*VDD – 3.1)V
LED pin voltage =(2*VDD – 3.1)V
000
001
010
011
100
101
110
111
LED pin voltage =(2*VDD – 3.1)V
reference
(note 2)
Except LED drive current
(note 1) IREF resistance value(kΩ) = 66 ÷ [LED set value (mA)] × 4.7(kΩ) , also [LED set value]
is possible to set with 22mA ~ 66mA.
(note 2)
Set a lower limit value 1.1V to be only 1ch in 3ch, and use the other 2ch by 2.0V or more
with LED_Vf.
(note 3)
External load: The total line resistance value of CPOUT pin ~ LED anode and LED
cathode ~ LED_X pin within 2Ω.
(note 4)
50% setting is an upper bound when 3ch becoming turning on at the same time.
MS1152 - E - 01
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[AK7864]
4.
LEDD block, Switching characteristics
EN
0.7VDD
0.3VDD
ts
CONTR/G/B
th
0.7VDD
0.7VDD
(high setting)
tcl
th
CONTR/G/B
(low setting)
tcl
0.3VDD
tlon
90%
LED current
10%
tloff
No.
tlon
tloff
ts
th
tcl
Item
LED current rise time
LED current fall time
Reset valid setup time
LEDB_EN(0.7AVDD):base
position
Count up setup time
LEDB_EN(0.3AVDD):base
position
Current set clearing
CONT_x:0.7VDD: base position
MS1152 - E - 01
min.
1
(VDD=3.135~3.465V ,Ta=0∼70°C, unless otherwise specified)
typ.
max.
Unit
Conditions
10
μsec
10
μsec
μsec
CONTR/G/B to
EN(0.7VDD)
1
μsec
1
μsec
8
EN(0.3VDD) to
CONTR/G/B
2010/09
[AK7864]
5.
PDN Switching characteristics
Tpd 1
3.135V
Power
Tstup
Tpd2
PDN
E
(VDD=3.135~3.465V ,Ta=0∼70°C, unless otherwise specified)
Item
Power down period 1
Power down period 2
Start up time
Symbol
Pin
Tpd1
PDN
Tpd2
PDN
Tstup
EN
Min.
150
150
Typ.
Max.
1
Unit
ns
ns
ms
Conditions
( note 1) Please make PDN and EN Lo when you turn on the power supply.
( note 2) LED's lighting after max.1msec after standing up of PDN.
6.
Power Down Characteristic
Item
Power Down Current
MS1152 - E - 01
(VDD=3.135~3.465V ,Ta=0∼70°C, unless otherwise specified)
Min.
Typ.
Max.
Unit.
Remarks
20
µA
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2010/09
[AK7864]
External circuit example
1µF
CONT_R
7
CONT_G
6
CONT_B
5
4
EN
PDN
3
IREF
2
MS1152 - E - 01
VDD
1
10µF
LED_B
8
AK7864
Top View
15
CP
16
CN
9
V SS
14
VSS
10
LED_ G
1µF
11
VSS
12
LED_R
13
CPOUT
4.7kΩ
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2010/09
[AK7864]
Package
1 Package dimension unit [mm]
3.00±0.07
B
1.80
1.50
9
8
13
5
16
1.50
1.80
3.00±0.07
A
12
0.30±0.07
4
1
0.22±0.05
C0.30
0.05 M S A B
0.50
0.05 S
0.12~ 0.18
A部
0.00~ 0.05
0.70
0.05MAX
0.75MAX
S
0.17~ 0.27
【 A部詳細図】
2 Marking
1.Marketing code
:7864
2.Date code
:XXXXX
7864
XXXXX
MS1152 - E - 01
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[AK7864]
IMPORTANT NOTICE
z These products and their specifications are subject to change without notice.
When you consider any use or application of these products, please make inquiries the sales
office of Asahi Kasei Microdevices Corporation (AKM) or authorized distributors as to current
status of the products.
z AKM assumes no liability for infringement of any patent, intellectual property, or other rights in the
application or use of any information contained herein.
z Any export of these products, or devices or systems containing them, may require an export
license or other official approval under the law and regulations of the country of export pertaining
to customs and tariffs, currency exchange, or strategic materials.
z AKM products are neither intended nor authorized for use as critical componentsNote1) in any
safety, life support, or other hazard related device or systemNote2), and AKM assumes no
responsibility for such use, except for the use approved with the express written consent by
Representative Director of AKM. As used here:
Note1) A critical component is one whose failure to function or perform may reasonably be
expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of
the device or system containing it, and which must therefore meet very high standards of
performance and reliability.
Note2) A hazard related device or system is one designed or intended for life support or
maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other
fields, in which its failure to function or perform may reasonably be expected to result in loss
of life or in significant injury or damage to person or property.
z It is the responsibility of the buyer or distributor of AKM products, who distributes, disposes of, or
otherwise places the product with a third party, to notify such third party in advance of the above
content and conditions, and the buyer or distributor agrees to assume any and all responsibility
and liability for and hold AKM harmless from any and all claims arising from the use of said
product in the absence of such notification.
MS1152 - E - 01
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