NPC SM8150AB

SM8150A
PMIC with White LED Driver
1. OVERVIEW
The SM8150A is a charge pump type white LED driver, with 2-system programmable LDOs (Low Dropout
Regulator), and step-down DC/DC converter power management IC. The white LED driver provides constantcurrent drive for 1 to 6 backlight white LED connected in parallel and 1 torch/strobe white LED. The charge
pump automatically selects between ×1 mode, ×1.5 boost mode, and ×2 boost mode in response to battery voltage, LED drive current, and VFLED (LED forward bias voltage drop) conditions in order to extend battery
drive life. The SM8150A operating mode settings are accessed using an I2C*1 interface, allowing LED drive
current, LDO voltage, output ON/OFF, and other settings to be controlled from a microcontroller.
*1. I2C-BUS is a registered trademark of NXP B. V.
2. FEATURES
■
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■
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■
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Optimum specifications for clamshell cellular
phone with camera
• LCD backlight: Main-4ch/Sub-2ch (max 25mA/ch)
• Camera flash: 1ch (max 300mA)
Power saving design by automatic mode selection
of charge pump
• Power at ×1.5 mode is reduced by 25% from ×2 mode
• Power at ×1 mode is reduced by 50% from ×2
mode, 33% from ×1.5 mode
I2C interface best match for cellular phone chipset
Selecting current value (torch/strobe) of flash LED
by SBN pin
Shutdown synchronized to microcontroller supply
by VEN pin
1 system of step-down DC/DC converter built-in
• Output: 1.2 to 3.0V@ max 500mA
2 systems of programmable LDO built-in
• Output: 1.5/1.8/2.5/2.6/2.8/3.0/3.1/3.3V@ max 300mA
Various protection circuits built-in
• Startup soft start circuit built-in
• Overtemperature thermal shutdown (TSD) circuit built-in
• Supply undervoltage lockout (UVLO) circuit built-in
Supply voltage range (VIN1 to VIN3): 2.7 to 4.6V
Logic operating voltage range (VEN) : 1.8 to 4.6V
White LED Driver
• Charge-pump frequency: 1.0MHz (typ)
• Charge-pump maximum output current: 450mA
• Backlight LED current: 25 ± 1.5mA/ch (max)
• Backlight LED relative accuracy: ± 3%
• Flash LED current: 300 ± 20mA (max)
DC/DC converter
• DC/DC converter output voltage: 1.2 to 3.0V (typ)
• DC/DC converter output current: 500mA (max)
• DC/DC converter operating frequency: 2.0MHz (typ)
• DC/DC converter voltage accuracy: ± 2%
LDO
• LDO output voltage: 1.5 to 3.3V (VIN = 3.6V)
• LDO output current: 300mA (max)
• LDO dropout voltage: 0.1V (typ)
• LDO voltage accuracy: ± 2%
Package: 28-pin QFN
3. TYPICAL APPLICATION CIRCUIT
1µF
1µF
3.6V
C1P
C1M C2P
C2M
VIN1
2.2µF
VOUT
4.7µF
PGND1
VIN2
DIN1
2.2µF
PGND2
DIN2
VIN3
DIN3
2.2µF
DIN4
DIN5
DIN6
SM8150A
Logic supply
VEN
DIN7
0.1µF
I2 C
LDOUT1
SCL
LDO1 output
2.2µF
SDA
LDOUT2
LDO2 output
2.2µF
Strobe
SBN
ON/OFF
100kΩ
FB
8pF
200kΩ
LX
VREF
0.1µF
2.2µH
GND1
2.2µF
GND2
DCOUT
(1.8V)
4. APPLICATIONS
■
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Cellular phone
Mobile equipment
5. ORDERING INFORMATION
Device
Package
SM8150AB
28-pin QFN
SEIKO NPC CORPORATION —1
SM8150A
6. PINOUT
LDOUT1
VIN3
LDOUT2
FB
PGND2
LX
VIN2
(Top view)
VREF
GND2
DIN7
DIN6
DIN5
GND1
DIN4
21
22
15
14
28
8
7
DIN3
DIN2
DIN1
VOUT
C1P
C2P
C2M
1
SDA
SCL
SBN
VEN
VIN1
C1M
PGND1
7. PIN DESCRIPTION
Number
Name
I/O
1
DIN3
O
LED drive current control output 3 (group A)*1
Description
2
DIN2
O
LED drive current control output 2 (group A)*1
3
DIN1
O
LED drive current control output 1 (group A)*1
4
VOUT
O
LED drive voltage output
5
C1P
–
Charge pump boost capacitor connection
6
C2P
–
Charge pump boost capacitor connection
7
C2M
–
Charge pump boost capacitor connection
8
PGND1
–
Ground (charge pump)
9
C1M
–
Charge pump boost capacitor connection
10
VIN1
–
Supply input (charge pump)
11
VEN
–
Supply input (logic)*2
12
SBN
I
Torch/strobe selecting voltage input (strobe when LOW)*3
13
SCL
I
I2C interface clock input*3
14
SDA
I/O
I2C interface data input*3
15
VIN2
–
Supply input (DC/DC converter)
16
LX
O
DC/DC converter coil switching output*4
17
PGND2
–
Ground (DC/DC converter)
18
FB
I
DC/DC converter feedback input
19
LDOUT2
O
LDO output 2*4
20
VIN3
–
Supply input (logic and LDOs)
21
LDOUT1
O
LDO output 1*4
22
VREF
O
Bypass capacitor connection
23
GND2
–
Ground
24
DIN7
O
LED drive current control output 7 (high-current LED)*1
25
DIN6
O
LED drive current control output 6 (group B)*1
26
DIN5
O
LED drive current control output 5 (group B)*1
27
GND1
–
Ground
28
DIN4
O
LED drive current control output 4 (group A)*1
*1. Connect to ground when no LED is connected.
*2. Connect to a supply with ≥ 1.8mA drive current capability. If pull-up resistors Rup are connected to SCL, SDA, and SBN, the current
consumption increases by the amount flowing through the pull-up resistances only. The current component for each of the 3 pins is
given by Iup [mA] = VEN [V] / Rup [kΩ].
*3. Pull-up or pull-down resistances are not built-in.
*4. Leave open circuit when not used (do not connect to ground).
SEIKO NPC CORPORATION —2
SM8150A
8. BLOCK DIAGRAM
VIN1
C1M C1P
VIN3
C2M C2P
VIN2
VOUT
Charge pump
1/ 1.5/ 2
DIN1
GND2
I2 C
interface
&
Control
logic
VREF
Thermal
shutdown
UVLO
SDA
SBN
GND1
VREF
DIN3
DIN4
DIN5
DIN6
Torch/
Strobe
SCL
OSC
Group A
VEN
Group B
Current control & Current detect
DIN2
Synchronous
step-down
DC/DC
converter
DIN7
LX
FB
Programmable
LDO
LDOUT1
Programmable
LDO
LDOUT2
PGND1
DCOUT
PGND2
SEIKO NPC CORPORATION —3
SM8150A
9. ABSOLUTE MAXIMUM RATINGS
GND = PGND = 0V
Parameter
Pins
Symbol
Rating
Unit
VIN1 to 3
VIN
−0.3 to 5.5
V
VEN
VEN
−0.3 to 5.5
V
SBN, SCL, SDA
VDATA
–0.3 to VEN + 0.3
V
All other input pins
VINPUT
–0.3 to VIN + 0.3
V
SDA
VOUT_ACK
–0.3 to VEN + 0.3
V
VOUT
VOUT_CP
5.5
V
All other output pins
VOUTPUT
–0.3 to VIN + 0.3
V
VOUT
IOUT_CP
600
mA
LX
IOUT_LX
1.2
A
LDOUT1 to 2
IOUT_LDO
1
A
Supply voltage
Logic operating voltage
Input voltage
Output voltage
Output current
Power dissipation
= 90°C /W)*1
W
TJMAX
+125
°C
TSTG
−55 to +125
°C
1.1 (θJ
PD
−
Junction temperature
Storage temperature
*1. When the SM8150A is mounted on a 40 × 60 × 1.6mm 2-layer board whose wiring pattern ratio is 130%.
Note. The device may suffer breakdown if any one of these parameter ratings is exceeded.
The thermal resistance θJ required for the operating environment is determined by the relationship with power
dissipation and operating temperature given below.
■
Maximum junction temperature: TJMAX = 125 [°C]
Operating temperature: Ta [°C]
Thermal resistance: θJ [°C/W]
PD =
(TJMAX − Ta)
θJ
2
1.5
PD [W]
■
■
θJ = 90°C/W
1
0.5
0
0
25
50
75
85
Ta [°C]
SM8150A power dissipation
SEIKO NPC CORPORATION —4
SM8150A
10. RECOMMENDED OPERATING CONDITIONS
VIN1 = VIN2 = VIN3, GND = PGND = 0V
Rating
Parameter
Pin
Supply voltage*1
Symbol
VIN1 to 3
Logic operating voltage
Input voltage
Conditions
Unit
min
typ
max
VIN_×1
×1 mode, IOUT = 0mA
2.7
3.6
4.6
V
VIN_×1.5
×1.5 mode, IOUT = 150mA
3.0
3.6
4.6
V
VIN_×2
×2 mode, IOUT = 450mA
3.3
3.6
4.6
V
VEN
VEN
1.8
2.8
4.6
V
SBN, SCL,
SDA
VDATA
0
−
VEN
V
Strobe time*2
DIN7
Torch LED current*2
tSTROBE
ILED7 ≥ 150mA
−
−
250
ms
ILED7
tTORCH > 250ms
−
−
150
mA
−30
25
+85
°C
−
Operating temperature
Ta
*1. Supply voltage and IOUT (LED)
When the white LED drive current is increased, the required supply voltage also increases. The supply is automatically switched in charge pump boost
mode, and cannot be manually selected. The forward-bias voltage drop VF of the LED is assumed to be ≤ 3.5V.
500
IOUT (LED) [mA]
400
300
200
100
0
2.5
3
3.5
4
4.5
5
VIN [V]
IOUT (LED) vs. VIN
*2. Torch and Strobe
Pin DIN7 is provided for connection to a high-current white LED. Two types of light modulation (dimming) data are available, switched by the SBN input
voltage. When SBN is HIGH, torch mode is selected. When SBN is LOW, strobe mode is selected. The recommended operating condition is high current with short ON times in strobe mode, and low current with longer ON times in torch mode. In strobe mode (SBN = LOW), high-current supply is the
main priority and, therefore, the current consumption is not optimized (see “Torch/Strobe Selecting”).
I2C data settings
DIN7 − Enable
1
DIN7 − Disable
1
1
1
1
1
*
*
*
*
1
0
*
*
SBN
Torch
Strobe
Dimming
Recommended operating conditions
H
ON
OFF
Torch
ILED7 < 150mA
L
OFF
ON
Strobe
Operating time < 250ms
H
OFF
OFF
−
−
L
OFF
OFF
−
−
*
*
SEIKO NPC CORPORATION —5
SM8150A
11. ELECTRICAL CHARACTERISTICS
11-1. Common Blocks
VIN = 3.6V, VEN = 2.8V, GND = PGND = 0V, Ta = 25°C unless otherwise noted.
Rating
Parameter
Pin
Standby current 1
VIN
Standby current 2
Current consumption*1
Symbol
Condition
VIN
UVLO operating voltage
–
TSD hysteresis
H-level input voltage 1
max
VEN = 0V, input/outputs no load
–
0.01
1
µA
ISTB2
VEN ≥ 1.8V, input/outputs no load
–
0.1
1
µA
IEN1
SCL = SDA = SBN = VEN
–
0.1
1
µA
IEN2
SBN = VEN = 2.8V
SCL, SDA: f = 400kHz
tr = tf = 300ns
signal amplitude = VEN × 90%
–
0.1
0.5
mA
IEN3
SBN = VEN = 4.6V
SCL, SDA: f = 400kHz
tr = tf = 300ns
signal amplitude = VEN × 90%
–
0.6
1.8
mA
tPOR
Design value
–
–
1
ms
VUVLO
TSD operating temperature
typ
ISTB1
VEN
Power-ON reset time*2
Unit
min
2.0
2.45
2.65
V
TSD
VIN falling
Design value
–
170
–
°C
TSDHYS
Design value
–
20
–
°C
VIH1
VEN ≥ 2.3V
1.8
–
–
V
VIL1
VEN ≥ 2.3V
–
–
0.6
V
VIH2
VEN < 2.3V
1.5
–
–
V
VIL2
VEN < 2.3V
–
–
0.3
V
H-level input current
IIH
VIH = VEN
–
–
1.0
µA
L-level input current
IIL
VIL = GND
–1.0
–
–
µA
L-level input voltage 1
H-level input voltage 2
L-level input voltage 2
SBN,
SCL,
SDA
*1. Excluding the current that flows to external circuit such as pull-up resistors.
IEN
A
Rup
Rup
VEN
0.1µF
Rup
SCL
SDA
SBN
*2. The time between when power is applied and the device enters standby mode.
Reference Data
Standby current 2 [µA]
0.5
0.4
0.3
0.2
0.1
0
2.7
3
3.3
3.6
3.9
4.2
4.5
VIN [V]
Standby current (VEN = 1.8V)
SEIKO NPC CORPORATION —6
SM8150A
11-2. White LED Driver
VIN = 3.6V, VEN = 2.8V, GND = PGND = 0V, Ta = 25°C unless otherwise noted.
Rating
Parameter
Pin
Current consumption*1
Symbol
VIN
Output voltage*2
VOUT
Output current
Charge pump frequency
C1M
Soft start time*3
DIN1 to 7
LED drive pin leakage current
LED current (max) 1
DIN1 to 6
LED current relative accuracy
LED current (max) 2
DIN7
Condition
Unit
min
typ
max
IDRV_×1
×1 mode, no load
–
0.3
1
mA
IDRV_×1.5
×1.5 mode, no load
–
4
8
mA
IDRV_×2
×2 mode, no load
–
5
10
mA
VOUT_CP
Boost ON, no load
4.6
4.9
5.2
V
IOUT_CP
Boost ON
–
–
450
mA
fOSC
0.85
1.0
1.15
MHz
tSS
–
1
3
ms
ILEAK1 to 7
Standby mode, DIN1 to 7 = VIN
–
0.01
1.0
µA
ILED1 to 6
×1 mode, ILED1 to 6 max setting
23.5
25.0
26.5
mA
∆ILED
×1 mode, ILED1 to 6 max setting
–3.0
–
+3.0
%
ILED7
×2 mode, ILED7 max setting
280
300
320
mA
*1. LDOUT1 to 2 and the DC/DC converter is disabled.
*2. Over voltage protection threshold.
*3. The time from when one of the DIN1 to 7 outputs is enabled until the LED turns ON.
Charge Pump Operating Mode Switching
The SM8150A switches between 3 charge pump operating modes; ×1 mode (VIN through mode), ×1.5 mode
(×1.5 charge pump boost), and ×2 mode (×2 charge pump boost), reducing the total power dissipation. These
selecting occurs automatically in internal circuits, and cannot be controlled by external signals. If the LED
current drops below the setting value while operating in ×1 or ×1.5 mode, each LED drive circuit detects the
undercurrent and the operating mode is automatically selected ×1 → ×1.5, ×1.5 → ×2. This occurs even if only
one LED undercurrent condition is detected among the 7-channel LED drive circuits, thus it is recommended
that LED has small VF variation to optimize the total efficiency. In ×1.5 or ×2 mode operating, the SM8150A
generates "a mode reset signal" internally once every 1 second. This signal forces to select the mode ×1.5 →
×1, ×2 → ×1.5.
Reference Data
7
100
5
80
×2
Efficiency [%]
IDRV [mA]
6
4
3
×1.5
2
×1
1
0
2.7
3
3.3
3.6
3.9
4.2
VIN [V]
Current consumption (No load)
60
40
20
4.5
0
3.0
3.3
3.6
3.9
4.2
4.5
VIN [V]
Efficiency (DIN1 to 6: 25mA, DIN7: 155mA)
SEIKO NPC CORPORATION —7
SM8150A
11-3. I2C Interface
VIN = 3.6V, VEN = 2.8V, GND = PGND = 0V, Ta = 25°C unless otherwise noted.
Rating
Parameter
Pin
SCL clock frequency
Symbol
SCL
SCL hold time
Condition
Unit
fSCL
SCL, SDA
SCL L-level pulsewidth
I2C start condition
tHD;STA
tLOW
SCL
SCL H-level pulsewidth
tHIGH
I2C start condition
min
typ
max
−
−
400
kHz
0.6
−
−
µs
1.3
−
−
µs
0.6
−
−
µs
0.6
−
−
µs
SCL setup time
tSU;STA
SDA data hold time
tHD;DAT
0.05
−
0.9
µs
SDA data setup time
tSU;DAT
100
−
−
ns
tr
−
−
300
ns
−
−
300
ns
0.6
−
−
µs
Rise time
SCL, SDA
Fall time
tf
SCL setup time
I2C stop condition
tSU;STO
Bus free time
tBUF
1.3
−
−
µs
Capacitive load for each bus line
Cb
−
−
400
pF
SDA
tf
tLOW
tBUF
tr
tr
tSU;DAT
tf
tHD;STA
SCL
tHD;DAT
tHD;STA
tHIGH
tSU;STA
S
tSU;STO
Sr
P
Note. S: START condition, Sr: repeated START condition, P: STOP condition
After a START condition, the slave address should be sent, and a data transfer should be terminated by
a STOP condition.
1st byte: Slave address
Start
2nd byte: Control data
SDA
Nth byte: Control data
ACK
M3
M2
D2
D1
9
1
2
7
8
ACK
Stop
M3
M2
D2
D1
ACK
1
2
7
8
9
SCL
1
2
7
8
9
SEIKO NPC CORPORATION —8
SM8150A
11-4. DC/DC Converter
VIN = 3.6V, VEN = 2.8V, GND = PGND = 0V, Ta = 25°C unless otherwise noted.
Rating
Parameter
Pin
Symbol
Condition
Unit
min
typ
max
Current consumption*1
VIN
IDD
No load, switching stopped
–
0.5
1.2
mA
Soft start time*2
LX
tSS
DCOUT = 1.8V
–
1
–
ms
DCOUT
VDCO
1.2
–
3.0
V
FB
VFB
0.588
0.6
0.612
V
DCOUT
IDCO
–
–
500
mA
fOSC
1.7
2.0
2.3
MHz
Output voltage range*3
FB pin voltage
LX pin output current
Switching frequency
Supply-side switch ON resistance
LX
GND-side switch ON resistance
LX pin leakage current
Line regulation
DCOUT
Load regulation
Overcurrent protection circuit
operating current
LX
IDCO = 1mA
RONP
ILX = 50mA
–
0.5
1.0
Ω
RONN
ILX = 50mA
–
0.4
0.8
Ω
–1.0
–
1.0
µA
ILEAKLX
Standby mode, LX = 1/2VIN
∆VOUT1
2.7 ≤ VIN ≤ 4.6V, IDCO = 1mA
–
10
–
mV
∆VOUT2
1mA ≤ IDCO ≤ 300mA
–
60
–
mV
ILIMITLX
Supply-side switch
0.8
1.2
1.7
A
*1. DIN1 to 7 and LDOUT1 to 2 outputs are disabled.
*2. The time from when the DC/DC converter is enabled until the output is stabilized.
*3. The DCOUT output voltage is determined by the external resistors R1 and R2, as given by the following equation. The SM8150A DC/DC converter
controls the output such that the FB pin voltage remains at 0.6V. The DCOUT voltage is given for values of R1 and R2 in the table on the right, where
R1 is a fixed 200kΩ resistance.
DCOUT =
Example
0.6 × (R1 + R2)
R2
FB
SM8150
8pF
DCOUT
DCOUT [V]
R1 [kΩ]
R2 [kΩ]
1.200
200
200
1.502
200
133
1.800
200
100
2.505
200
63
2.600
200
60
2.802
200
54.5
3.000
200
50
LX
2.2µH
2.2µF
R1
0.6V
R2
SEIKO NPC CORPORATION —9
SM8150A
100
1
80
0.8
IDD [mA]
Efficiency [%]
Reference Data
60
40
0.6
0.4
0.2
20
0
2.7
0
1
10
100
1000
3
3.3
IDCO [mA]
Efficiency − Load current
1.90
1.85
IDCO = 300mA
VDCO [V]
VDCO [V]
1.85
1.80
1.70
2.7
3.9 4.2 4.5
Current consumption (No load, switching stopped)
1.90
1.75
3.6
VIN [V]
1.80
1.75
IDCO = 1mA
1.70
3.0
3.3
3.6
3.9
4.2
VIN [V]
4.5
0
100
200
300
400
500
IDCO [mA]
Line regulation
Load regulation
IDCO = 300mA
IDCO = 500mA
SEIKO NPC CORPORATION —10
SM8150A
11-5. LDO
VIN =3.6V, VEN = 2.8V, GND = PGND = 0V, Ta = 25°C unless otherwise noted.
Rating
Parameter
Pin
Symbol
Current consumption*1
Condition
Unit
min
typ
max
IDD_LDO
No load
–
0.35
0.8
mA
GND pin current
IGND_LDO
ILDO = 50mA,
IGND_LDO = IDD_LDO − ILDO
–
0.35
1.2
mA
Soft start time*2
tSS_LDO
ILDO = 1mA
–
1
–
ms
Output voltage
VLDO
Output current
ILDO
VIN
Dropout voltage
VDROP
LDOUT1 to 2
∆VOUT1
Line Regulation
∆VOUT2
Load Regulation
Overcurrent protection circuit
operating current
ILDO = 1mA, VLDO ≤ VIN – 0.3V
See “Output voltage table”.
–
–
300
mA
ILDO = 100mA
–
0.1
0.2
V
ILDO = 200mA
–
0.2
0.4
V
ILDO = 300mA
–
0.3
0.6
V
3.6V ≤ VIN ≤ 4.6V,
VLDO (setting) = 3V, ILDO = 30mA
–
20
60
mV
VLDO (setting) = 3V,
5mA ≤ ILDO ≤ 100mA
–
10
30
mV
VLDO (setting) = 3V,
5mA ≤ ILDO ≤ 200mA
–
20
60
mV
350
650
950
mA
VIN = 3V,
VLDO (setting)
= 3.3V
IOS
*1. DIN1 to 7 and the DC/DC converter is disabled.
*2. The time taken from when either of LDOUT1 to 2 is enabled until the output is stabilized.
Output voltage table
Setting
min
typ
max
unit
1.5
1.470
1.5
1.530
V
1.8
1.764
1.8
1.836
V
2.5
2.450
2.5
2.550
V
2.6
2.548
2.6
2.652
V
2.8
2.744
2.8
2.856
V
3.0
2.940
3.0
3.060
V
3.1
3.038
3.1
3.162
V
3.3
3.234
3.3
3.366
V
SEIKO NPC CORPORATION —11
SM8150A
Reference Data
0
-10
PSRR [dB]
Output noise [µV/ √ Hz]
10.00
1.00
0.10
-20
-30
-40
-50
-60
0.01
10
100
1000
10000
10
100000
100
1000
Output noise
VIN3: 2.2µF
VREF: 0.1µF
LDOUT: 2.2µF
Ripple rejection
VIN = 3.6V
VLDO = 1.8V
ILDO = 10mA
VIN3: 0µF, 500mVp-p
VREF: 0.1µF
LDOUT: 2.2µF
Step response 1
∆VLDO [mV]
∆VLDO [mV]
VLDO = 2.8V
-10
-20
VLDO = 1.8V
-30
-40
0
50
VIN = 3.6V
VLDO = 1.8V
ILDO = 10mA
Step response 2
10
0
10000 100000 1000000
f [Hz]
f [Hz]
100 150 200 250 300
15
10
5
0
-5
-10
-15
-20
-25
-30
-35
2.7
ILDO [mA]
VLDO = 1.8V
VLDO = 2.8V
3
3.3
3.6
3.9
4.2 4.5
VIN [V]
Load regulation
Line regulation
0
1
IGND_LDO [mA]
∆VLDO [mV]
-50
-100
-150
-200
-250
-300
-350
0
100
200
300
ILDO [mA]
Dropout voltage (VLDO = 2.8V)
0.8
0.6
0.4
0.2
0
0
100
200
ILDO [mA]
300
GND pin current (VLDO = 1.8V)
SEIKO NPC CORPORATION —12
SM8150A
12. FUNCTIONAL DESCRIPTION
12-1. Startup Method
The SM8150A enters standby mode when the VIN supply is applied. After the VEN supply is applied, standby
mode is released and operation commences when any one of the DIN1 to 4, DIN5 to 6, DIN7, LDOUT1,
LDOUT2 outputs or the DC/DC converter is enabled.
12-2. Standby Mode
In standby mode, all SM8150A circuit operation stops, reducing the current consumption. After the VIN supply is applied, the built-in power-ON reset circuit initializes the registers to their default values (see table 1)
and the device enters standby mode. Also, when the VEN supply is turned OFF (0V), the registers are initialized to their default values and the device enters standby mode. However, when all the outputs are disabled
(enable settings 1 and 2), the register values are stored and the device enters standby mode.
12-3. I2C Interface
The individual SM8150A settings are set using an I2C interface. The SM8150A has a fixed 8-bit address (slave
address) and the device must be addressed before inputting each data setting. The set data has an MSB first 8bit data structure. The first 3 bits select the register, and the next 5 bits are the write data. Each register is writeonly, and cannot be read. Transfer speed is in fast mode (400kbit/s).
12-3-1. Basic cycle
SDA
SCL
Start condition
Stop condition
I2C start/stop condition
Steps (1) to (4) represent the basic data input cycle.
(1) Start condition
(2) 1st byte (slave address input)
(3) 2nd byte to nth byte (settings data input)
(4) Stop condition
Data transfer begins with the start condition, which is when the SDA input voltage changes from HIGH to
LOW while the SCL input voltage is HIGH. Similarly, data transfer ends with the stop condition, which is
when the SDA input voltage changes from LOW to HIGH while the SCL input voltage is HIGH. Immediately
after each byte (8 bits) in steps (2) and (3), 1 clock cycle is used as an ACK (Acknowledge) cycle. The
SM8150A acknowledges that it has recognized the slave address in the first byte by taking the SDA line LOWlevel output while the ACK clock cycle is HIGH. No signal is output if the slave address is not recognized. The
second to nth bytes are always acknowledged by a LOW-level output bit, regardless of the received data content. The second and successive bytes are received and the corresponding setting is updated until the stop condition is input to the device.
SEIKO NPC CORPORATION —13
SM8150A
12-3-2. 1st byte: slave address
A6
A5
A4
A3
A2
A1
A0
R/W
0
0
0
1
0
0
1
0
12-3-3. 2nd byte to nth byte: data settings
Data settings summary
Mode select
Function
Set data
M3
M2
M1
D5
D4
D3
D2
D1
MSB
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
LSB
Main group LED dimmer setting (DIN1 to 4)
0
0
0
Sub-group LED dimmer setting (DIN5 to 6)
0
0
1
Torch LED dimmer setting (DIN7)
0
1
0
Strobe LED dimmer setting (DIN7)
0
1
1
LDO1 output voltage setting
1
0
0
0*1
0*1
LDO2 output voltage setting
1
0
1
0*1
0*1
Enable setting 2*2 (DC/DC converter)
1
1
0
Buck
Enable
0*1
0*1
0*1
0*1
Enable setting 1*2 (DIN1 to 7, LDO1 to 2)
1
1
1
DIN1 to 4
Enable
DIN5 to 6
Enable
DIN7
Enable
LDO1
Enable
LDO2
Enable
32-step dimming control
(see table 2)
8-step voltage settings
(see table 3)
*1. Setting used by NPC for testing. Always input 0 for normal operation.
*2. Enable settings are 1 for enabled, 0 for disabled.
12-3-4. Data input precautions
The VIN supply is applied first, and data input should commence after an interval of ≥ 1ms has elapsed after
the VEN supply is applied.
VIN
VEN
1ms
ACK
Start
0 0 0 1 0 0 1 0
SDA
Slave address
The LDO set voltage is changed using the following procedure. First, a) set to disabled, next b) change the
voltage setting, and then c) set to enabled. The gap between steps a) and c) should be ≥ 0.3ms.
Example
ACK
0 0 0 1 0 0 1 0
Start Slave address
ACK
ACK
ACK
1 1 1 * * * 0 *
1 0 0 0 0 1 1 1
1 1 1 * * * 1 *
LDO1 disable
LDO1 set (3.1V)
LDO1 enable
Stop
0.3ms
SEIKO NPC CORPORATION —14
SM8150A
12-4. Torch/Strobe Selecting
The DIN7 pin LED drive current, when DIN7 is enabled, can be switched by the input voltage on the SBN pin.
When SBN is HIGH, torch LED dimming is selected. When SBN is LOW, strobe LED dimming is selected.
The SM8150A automatically switches the charge pump operating mode (×1, ×1.5, ×2 boost mode) to optimize
the power consumption. However, when SBN is LOW the degree of boost is selected in the direction of
increased boost only. That is, selecting in order of ×1 → ×1.5 → ×2 boost only, ×2 → ×1.5 → ×1 selecting does
not occur.
12-5. Thermal Shutdown Circuit (TSD)
If for whatever reason the chip temperature reaches approximately 170°C, the overtemperature protection thermal shutdown (TSD) circuit operates, stopping all output. Turn on occurs the IC cools by approximately
150°C.
12-6. Undervoltage Lockout Circuit (UVLO)
If the VIN supply voltage falls below 2.45V, the supply undervoltage lockout (UVLO) circuit operates, initializing the registers to their default values and putting the device in standby mode. In this case, all data settings
must be re-input.
12-7. Register Settings Table
Table 1. Default settings (all disabled)
Mode select
Mode
Set data
M3
M2
M1
D5
D4
D3
D2
D1
MSB
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
LSB
Main group LED dimmer setting (DIN1 to 4)
0
0
0
0
0
0
0
0
Sub-group LED dimmer setting (DIN5 to 6)
0
0
1
0
0
0
0
0
Torch LED dimmer setting (DIN7)
0
1
0
0
0
0
0
0
Strobe LED dimmer setting (DIN7)
0
1
1
0
0
0
0
0
LDO1 output voltage setting
1
0
0
0
0
0
0
0
LDO2 output voltage setting
1
0
1
0
0
0
0
0
Enable setting 2 (DC/DC converter)
1
1
0
0
0
0
0
0
Enable setting 1 (DIN1 to 7, LDO1 to 2)
1
1
1
0
0
0
0
0
SEIKO NPC CORPORATION —15
SM8150A
Table 2. LED drive current settings (not guaranteed values)
D5
D4
D3
D2
D1
Data 3
Data 4
Data 5
Data 6
LSB
DIN1 to 4
DIN5 to 6
DIN7 (Torch)
DIN7 (Strobe)
Unit
0
0
0
0
0
0
0
0
0
mA
0
0
0
0
1
0.8
0.8
9.7
9.7
mA
0
0
0
1
0
1.6
1.6
19.4
19.4
mA
0
0
0
1
1
2.4
2.4
29.0
29.0
mA
0
0
1
0
0
3.2
3.2
38.7
38.7
mA
0
0
1
0
1
4.0
4.0
48.4
48.4
mA
0
0
1
1
0
4.8
4.8
58.1
58.1
mA
0
0
1
1
1
5.6
5.6
67.7
67.7
mA
0
1
0
0
0
6.5
6.5
77.4
77.4
mA
0
1
0
0
1
7.3
7.3
87.1
87.1
mA
0
1
0
1
0
8.1
8.1
96.8
96.8
mA
0
1
0
1
1
8.9
8.9
106
106
mA
0
1
1
0
0
9.7
9.7
116
116
mA
0
1
1
0
1
10.5
10.5
126
126
mA
0
1
1
1
0
11.3
11.3
135
135
mA
0
1
1
1
1
12.1
12.1
145
145
mA
1
0
0
0
0
12.9
12.9
155
155
mA
1
0
0
0
1
13.7
13.7
165
165
mA
1
0
0
1
0
14.5
14.5
174
174
mA
1
0
0
1
1
15.3
15.3
184
184
mA
1
0
1
0
0
16.1
16.1
194
194
mA
1
0
1
0
1
16.9
16.9
203
203
mA
1
0
1
1
0
17.7
17.7
213
213
mA
1
0
1
1
1
18.5
18.5
223
223
mA
1
1
0
0
0
19.4
19.4
232
232
mA
1
1
0
0
1
20.2
20.2
242
242
mA
1
1
0
1
0
21.0
21.0
252
252
mA
1
1
0
1
1
21.8
21.8
261
261
mA
1
1
1
0
0
22.6
22.6
271
271
mA
1
1
1
0
1
23.4
23.4
281
281
mA
1
1
1
1
0
24.2
24.2
290
290
mA
1
1
1
1
1
25.0
25.0
300
300
mA
Note. The values of the table 2 “LED drive current settings” are not guaranteed. The actual current values will spread around the values in the table. Especially the variation in 0.8mA setting is wide, and some of actual current may become 0mA. We recommend the usage that the minimum LED driving
current value is set at 1.6mA at the brightness adjustment.
Table 3. LDO output voltage settings (not guaranteed values)
D5
D4
D3
D2
D1
Data 3
Data 4
Data 5
Data 6
LSB
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LDOUT1
LDOUT2
Unit
0
1.5
1.5
V
1
1.8
1.8
V
1
0
2.5
2.5
V
1
1
2.6
2.6
V
1
0
0
2.8
2.8
V
1
0
1
3.0
3.0
V
0
1
1
0
3.1
3.1
V
0
1
1
1
3.3
3.3
V
SEIKO NPC CORPORATION —16
SM8150A
13. TYPICAL APPLICATION CIRCUITS
1µF
1µF
3.6V
C1P
C1M C2P
C2M
VIN1
2.2µF
VOUT
4.7µF
PGND1
VIN2
DIN1
2.2µF
PGND2
DIN2
VIN3
DIN3
2.2µF
DIN4
DIN5
DIN6
SM8150A
Logic supply
VEN
DIN7
0.1µF
2
I C
LDOUT1
SCL
LDO1 output
2.2µF
SDA
LDOUT2
LDO2 output
2.2µF
Strobe
SBN
ON/OFF
100kΩ
FB
8pF
200kΩ
LX
VREF
0.1µF
2.2µH
GND1
GND2
2.2µF
DCOUT
(1.8V)
Note. A 2.2µF bypass capacitor should be connected between the VOUT and GND pins. A 4.7µF or greater capacitor value may cause an unstable output voltage condition. Any unused LED drive pins (DIN1 to DIN7) should be connected to GND. If the LDOUT1/2 or LX pins are not used, they
should be left open circuit, and not connected to GND or power supply.
SEIKO NPC CORPORATION —17
SM8150A
13-1. DIN1 to 3, DIN5, DIN7 (Strobe), and LDO1
1µF
1µF
VIN "ON"
3.6V
C1P C1M C2P C2M
VIN1
VEN "ON"
VOUT
4.7µF
1ms
2.2µF
PGND1
VIN2
I 2 C address transfer
00010010
DIN1
2.2µF
PGND2
DIN2
VIN3
DIN3
2.2µF
Data transfer
00011111
DIN1 to 4 set to 25mA
Data transfer
00111010
DIN5 to 6 set to 21mA
Data transfer
01000000
Torch set to 0mA
Data transfer
01110000
Strobe set to 155mA
Data transfer
10000111
LDO1 set to 3.3V
Data transfer
11111010
DIN1 to 6, LDO1: Enable
Data transfer
111**1**
DIN7: Enable
(Waiting for SBN = Low)
DIN4
DIN5
DIN6
2.8V
VEN
10kΩ
10kΩ
SM8150A
DIN7
10kΩ
0.1µF
SCL
I2 C
SDA
H: Strobe OFF (Torch)
LDOUT1
LDO1 output
2.2µF
LDOUT2
LDOUT2: Leave open circuit.
Do not connect to ground.
SBN
L: Strobe ON
SBN = Low, 200ms 200ms Strobe ON
FB
VREF
LX
0.1µF
GND1
LX: Leave open circuit.
Do not connect to ground
or power supply.
Data transfer
111**0**
GND2
VEN "OFF"
DIN7: Disable
LEDs OFF,
LDO1 output stopped
Standby mode
■
Unused pins
• DIN4 and DIN6: Connect to GND.
• FB: Connect to GND.
• LDOUT2: Leave open circuit, do not connect to GND.
• LX: Leave open circuit, do not connect to GND or power supply.
■
Logic-level signal input pins
Connect pull-up resistors to SCL, SDA, and SBN for pull-up to the VEN supply level. The resistances
should be of the order of 1k to 10kΩ. The optimal resistance will vary with the actual mounting conditions.
SEIKO NPC CORPORATION —18
SM8150A
13-2. DIN1 to 2, DIN5 to 6, DIN7 (Torch), and DC/DC Converter
1µF
1µF
VIN "ON"
3.6V
C1P C1M C2P C2M
VEN "ON"
VOUT
VIN1
1ms
2.2µF
4.7µF
I 2 C address transfer
00010010
PGND1
VIN2
DIN1
PGND2
DIN2
2.2µF
VIN3
DIN3
2.2µF
Data transfer
00011111
DIN1 to 4 set to 25mA
Data transfer
00110011
DIN5 to 6 set to 15.3mA
Data transfer
01000101
Torch set to 48.4mA
Data transfer
01100000
Strobe set to 0mA
Data transfer
11111000
DIN1 to 6: Enable
Data transfer
11010000
DC/DC converter: Enable
Data transfer
111**1**
DIN7: Enable
(Torch lighting)
Data transfer
111**0**
DIN7: Disable
(Torch OFF)
DIN4
DIN5
DIN6
2.8V
VEN
10kΩ
10kΩ
SM8150A
DIN7
10kΩ
0.1µF
SCL
2
LDOUT1
LDOUT1: Leave open circuit.
Do not connect to ground.
LDOUT2
LDOUT2: Leave open circuit.
Do not connect to ground.
I C
SDA
SBN
100kΩ
FB
8pF
VREF
VEN "OFF"
2.2µH
0.1µF
GND1
200kΩ
LX
GND2
2.2µF
DCOUT
(1.8V)
LEDs OFF,
DC/DC converter stopped
Standby mode
■
Unused pins
• DIN3 and DIN4: Connect to GND.
• LDOUT1 and LDOUT2: Leave open circuit, do not connect to GND.
■
Logic-level signal input pins
Connect pull-up resistors to SCL, SDA, and SBN for pull-up to the VEN supply level. The resistances
should be of the order of 1k to 10kΩ. The optimal resistance will vary with the actual mounting conditions.
SEIKO NPC CORPORATION —19
SM8150A
14. USAGE NOTES
14-1. External Capacitor Type
The external capacitors connected to the SM8150A should be multi-layer ceramic capacitors, with low temperature coefficient X5R or X7R class (EIA standard) multi-layer ceramic capacitors recommended. Use of high
temperature coefficient Z5U or Y5V class multi-layer ceramic capacitors may cause an unstable output voltage
condition and should be avoided.
Capacitor temperature coefficient 3-letter codes (EIA standard)
Lower category
temperature
Upper category
temperature
Maximum deviation in capacitance
from +25°C (0V DC) value
X = −55°C
5 = +85°C
F = ± 7.5%
Y = −30°C
6 = +105°C
P = ± 10%
Z = +10°C
7 = +125°C
R = ± 15%
8 = +150°C
S = ± 22%
T = +22%/−33%
U = +22%/−56%
V = +22%/−82%
Selection
: X5R characteristics
14-2. VIN Supply Input Capacitor
In some cases, the printed board component layout may affect the stability of the output voltages. In such
cases, the VIN power supply capacitor should be increased or an additional capacitor connected.
14-3. Mounting
The package rear surface is metallic, and can be connected to the printed circuit board pattern as a heatsink.
The connected pattern should be tied to GND level. Furthermore, use of a thermal via structure on the PCB or
other technology should be used to provide sufficient heat dissipation. Use a printed circuit board with 4 or
more layers. The PCB wiring ratio*1 should exceed 200%, where the wiring ratio is the sum total of printed
wiring pattern surface area relative to the circuit board surface area.
*1. Determining the wiring pattern ratio
Example: 4-layer board with the same wiring pattern on 4 layers (left), where the wiring pattern surface
area on each layer is represented by S1, and the non-wired surface area is represented by S2. The wiring
pattern is connected directly to the IC, and each layer’s wiring pattern is connected to the IC by through
holes. The circuit board surface area seen from above is S1 + S2. First, calculate the board surface area,
here represented by S1 + S2. Next, calculate the wiring pattern surface area on each layer connected to the
IC, represented here by S1. Calculate the total wiring pattern surface area for all 4 layers, in this example 4
× S1. Finally, calculate the wiring ratio percentage using the following equation: (Wiring ratio) = (Total
wiring pattern surface area connected to the IC) / (PCB surface area) × 100. In this example, 4 × S1/(S1 +
S2) × 100 [%], or a wiring ratio of 200% when S1 = S2.
S1
S2
SEIKO NPC CORPORATION —20
SM8150A
15. PACKAGE DIMENSION
(Unit: mm)
Top view
Bottom view
4.0 ± 0.07
2.8
2.8
0.3 ± 0.07
0.4
4.0 ± 0.07
A
6 = 2.4 ± 0.05
0.8
B
0.7 ± 0.05
0.2 S
φ 0.05 M S A B
0.05 S
0.4
0.15 ± 0.03
S
0.07 ± 0.03
C 0.3
0.18 ± 0.05
0.02 S A B
16. FOOTPRINT PATTERN
4.6 ± 0.1
3.2 ± 0.1
4.6 ± 0.1
3.2 ± 0.1
2.6
0.4 × 6 = 2.4
0.3
0.21 ± 0.05
0.4 × 6 = 2.4
0.7 ± 0.1
0.3
2.6
SEIKO NPC CORPORATION —21
SM8150A
Please pay your attention to the following points at time of using the products shown in this document.
The products shown in this document (hereinafter “Products”) are not intended to be used for the apparatus that exerts harmful influence on
human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such
use from SEIKO NPC CORPORATION (hereinafter “NPC”). Customers shall be solely responsible for, and indemnify and hold NPC free and
harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right
to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that
the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties.
Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document.
Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products,
and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or
modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in
compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested
appropriately take steps to obtain required permissions or approvals from appropriate government agencies.
SEIKO NPC CORPORATION
15-6, Nihombashi-kabutocho, Chuo-ku,
Tokyo 103-0026, Japan
Telephone: +81-3-6667-6601
Facsimile: +81-3-6667-6611
http://www.npc.co.jp/
Email: [email protected]
NC0506DE
2007.06
SEIKO NPC CORPORATION —22