SC627A
LED Light Management Unit
POWER MANAGEMENT
Features
Input supply voltage range — 3.0V to 5.5V
Charge pump modes — 1x, 1.5x and 2x
Four programmable current sinks with 32 steps from
0.5mA to 25mA
Flash LED — 700mA max in flash mode, 250mA max
continuous for spotlight
Two programmable 200mA low-noise LDO regulators
Charge pump frequency — 250kHz
I
2
C compatible interface —
up to 400kHz
Backlight current accuracy ±1.5% typical
Backlight current matching ±0.5% typical
Programmable fade-in/fade-out for main backlight
External flash control pin to sync with camera
Optional 1s flash time out
Automatic sleep mode (LEDs off )
—
I
Q
= 100μA
Low shutdown current — 0.1μA (typical)
Ultra-thin package — 3mm x 3mm x 0.6mm
Lead-free and halogen-free
WEEE and RoHS compliant
Charge Pump, 4 LEDs, 700mA Flash LED,
Dual LDOs, and I
2
C Interface
Description
The SC627A is a high efficiency charge pump LED driver
using Semtech’s proprietary mAhXLife
TM
technology.
Performance is optimized for use in single-cell Li-ion
battery applications.
The charge pump provides backlight current in
conjunction with four matched current sinks. It also can
supply continuous or bursted current to a flash LED using
the dedicated flash driver current sink. The load and
supply conditions determine whether the charge pump
operates in 1x, 1.5x, or 2x mode. An optional fading feature
that gradually adjusts the backlight current is provided to
simplify control software. A flash-timeout feature disables
the flash if active for longer than 1 second. The SC627A also
provides two low-dropout, low-noise linear regulators for
powering a camera module or other peripheral circuits.
The SC627A uses an I
2
C compatible serial interface. The
interface controls all functions of the device, including
backlight and flash currents as well as two LDO voltage
outputs. The flash/spotlight output is triggered via either
the I
2
C interface or a dedicated pin.
In sleep mode, the device reduces quiescent current to
100μA while continuing to monitor the serial interface.
The two LDOs can be enabled when the device is in sleep
mode. Total current reduces to 0.1μA
in shutdown.
Applications
Cellular phone backlighting and flash
PDA backlighting and flash
Camera I/O and core power
Typical Application Circuit
MAIN BACKLIGHT
V
BAT
C
IN
2.2μF
VIN
I
2
C Data
I C Clock
Flash Control
Enable Control
2
FLASH
VOUT
SDA
SCL
FLEN
EN
BYP
SC627A
BL
1
BL
2
BL
3
BL
4
FL
LDO
1
LDO
2
C1-
C2+ C2-
C2
2.2μF
C
OUT
4.7μF
C
BYP
22nF
AGND
PGND
C1+
C1
2.2μF
V
LDO1
= 2.5V to 3.3V
V
LDO2
= 1.5V to 1.8V
C
LDO1
1μF
C
LDO2
1μF
US Patents: 6,504,422; 6,794,926
October 19, 2009
© 2009 Semtech Corporation
1
SC627A
Pin Configuration
Ordering Information
Device
C1+
C2+
C1-
VIN
VOUT
Package
MLPQ-UT-20 3×3
Evaluation Board
SC627AULTRT
(1)(2)
SC627AEVB
20
C2-
PGND
FL
BL1
BL2
1
2
3
4
5
6
19
18
17
16
15
LDO1
LDO2
BYP
EN
SDA
TOP VIEW
Notes:
(1) Available in tape and reel only. A reel contains 3,000 devices.
(2) Lead-free packaging only. Device is WEEE and RoHS compliant,
and halogen-free.
14
13
12
T
11
9
10
7
8
AGND
MLPQ-UT-20; 3x3, 20 LEAD
θ
JA
= 35°C/W
Marking Information
627A
yyww
xxxx
yyww = Date Code
xxxx = Semtech Lot No.
FLEN
SCL
BL3
BL4
2
SC627A
Absolute Maximum Ratings
VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0
VOUT (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0
C1+, C2+ (V) . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (V
OUT
+ 0.3)
Pin Voltage - All Other Pins (V) . . . . . . . . . . . -0.3 to (V
IN
+ 0.3)
VOUT Short Circuit Duration . . . . . . . . . . . . . . . . Continuous
VLDO1, VLDO2, Short Circuit Duration . . . . . . Continuous
ESD Protection Level
(1)
(kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Recommended Operating Conditions
Ambient Temperature Range (°C) . . . . . . . . -40 < T
A
< +85
VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 < V
IN
< 5.5
VOUT (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 < V
OUT
< 5.25
Voltage Difference between any two LEDs (V) . . . . . . < 1.2
Thermal Information
Thermal Resistance, Junction to Ambient
(2)
(°C/W) . . . . 35
Maximum Junction Temperature (°C) . . . . . . . . . . . . . . +150
Storage Temperature Range (°C) . . . . . . . . . . . . -65 to +150
Peak IR Reflow Temperature (10s to 30s) (°C) . . . . . . . +260
Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters
specified in the Electrical Characteristics section is not recommended.
NOTES:
(1) Tested according to JEDEC standard JESD22-A114-B.
(2) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
Electrical Characteristics
Unless otherwise noted, T
A
= +25°C for Typ, -40ºC to +85°C for Min and Max, T
J(MAX)
= 125ºC, V
IN
= 3.0V to 4.2V, C
IN
= C
1
= C
2
= 2.2μF,
C
OUT
= 4.7μF (ESR = 0.03Ω), ΔV
F
≤ 1.2V
(1)
Parameter
Supply Specifications
Shutdown Current
Symbol
Conditions
Min
Typ
Max
Units
I
Q(OFF)
Shutdown, V
IN
= 4.2V
Sleep (LDOs off ), EN = V
IN
Sleep (LDOs on), EN = V
IN
,
V
IN
> (V
LDO
+ 300mV), I
LDO
< 200mA
0.1
100
220
3.8
4.6
4.6
2
160
μA
μA
340
4.65
5.85
5.85
mA
Total Quiescent Current
I
Q
Charge pump in 1x mode, 4 backlights on
Charge pump in 1.5x mode, 4 backlights on
Charge pump in 2x mode, 4 backlights on
Fault Protection
Output Short Circuit
Current Limit
Over-Temperature
Flash Mode Safety Timer
(2)
I
OUT(SC)
T
OTP
t
FL(MAX)
Flash sink active
0.75
VOUT pin shorted to GND
300
160
1.00
1.25
mA
°C
s
3
SC627A
Electrical Characteristics (continued)
Parameter
Fault Protection (continued)
Charge Pump
Over-Voltage Protection
V
OVP
V
UVLO
Undervoltage Lockout
V
UVLO-HYS
Charge Pump Electrical Specifications
Maximum Total Output
Current
Backlight Current Setting
Flash Current Setting
Backlight Current Accuracy
Backlight Current Matching
Flash Current Accuracy
1x Mode to 1.5x Mode
Falling Transition Voltage
1.5x Mode to 1x Mode
Hysteresis
1.5x Mode to 2x Mode
Falling Transition Voltage
2x Mode to 1.5x Mode
Hysteresis
Current Sink Off-State
Leakage Current
Pump Frequency
LDO Electrical Specifications
LDO1 Voltage Setting
V
LDO1
V
LDO2
V
LDO1,
V
LDO2
Range of nominal settings
in 100mV increments
Range of nominal settings
in 100mV increments
V
IN
= 3.7V, I
LDO
= 1mA
LDO1, I
LDO1
= 1mA, V
OUT
= 2.8V
Line Regulation
ΔV
LINE
LDO2, I
LDO2
= 1mA, V
OUT
= 1.8V
1.3
4.8
2.5
3.3
V
I
OUT(MAX)
I
BL
I
FL
I
BL_ACC
I
BL-BL
I
FL_ACC
V
TRANS1x
V
HYST1x
V
TRANS1.5x
V
HYST1.5x
I
BLn
f
PUMP
V
IN
> 3.4V, sum of all active LED currents,
V
OUT(MAX)
= 4.0V
Nominal setting for BL1 thru BL4
Nominal setting for FL
V
IN
= 3.7V, I
BL
= 12mA, T
A
= 25°C
V
IN
= 3.7V, I
BL
= 12mA
(3)
V
IN
= 3.7V, I
FL
= 500mA, T
A
= 25°C
I
OUT
= 40mA, I
BLn
= 10mA, V
OUT
= 3.2V
I
OUT
= 40mA, I
BLn
= 10mA, V
OUT
= 3.2V
I
OUT
= 40mA, I
BLn
= 10mA, V
OUT
= 4.0V
(4)
I
OUT
= 40mA, I
BLn
= 10mA, V
OUT
= 4.0V
(4)
V
IN
= V
BLn
= 4.2V
V
IN
= 3.2V
800
0.5
50
-8
-3.5
-15
3.27
±1.5
±0.5
25
700
+8
+3.5
+15
mA
mA
mA
%
%
%
V
300
mV
VOUT pin open circuit, V
OUT
= V
OVP
rising threshold
Decreasing V
IN
5.3
5.7
2.4
6.0
V
V
Symbol
Conditions
Min
Typ
Max
Units
250
mV
2.92
V
300
mV
0.1
250
1
μA
kHz
LDO2 Voltage Setting
LDO1, LDO2 Output
Voltage Accuracy
1.5
1.8
V
-3.5
±3
+3.5
%
2.1
7.2
mV
4
SC627A
Electrical Characteristics (continued)
Parameter
Symbol
Conditions
Min
Typ
Max
Units
LDO Electrical Specifications (continued)
V
LDO1
= 3.3V, V
IN
= 3.7V,
I
LDO1
= 1mA to 100 mA
V
LDO2
= 1.8V, V
IN
= 3.7V,
I
LDO2
= 1mA to 100 mA
I
LDO1
= 100mA
200
2.5V < V
LDO1
< 3V, f < 1kHz, C
BYP
= 22nF, I
LDO1
= 50mA,
V
IN
= 3.7V with 0.5V
P-P
ripple
f < 1kHz, C
BYP
= 22nF, I
LDO2
= 50mA,
V
IN
= 3.7V with 0.5V
P-P
ripple
LDO1, 10Hz < f < 100kHz, C
BYP
= 22nF, C
LDO
= 1μF,
I
LDO1
= 50 mA, V
IN
= 3.7V, 2.5V < V
LDO1
< 3V
LDO2, 10Hz < f < 100kHz, C
BYP
= 22nF,
C
LDO
= 1μF, I
LDO2
= 50 mA, V
IN
= 3.7V
50
dB
60
100
25
mV
20
150
mV
mA
Load Regulation
ΔV
LOAD
Dropout Voltage
(5)
Current Limit
V
D
I
LIM
PSRR
LDO1
PSRR
LDO2
e
n-LDO1
Power Supply
Rejection Ratio
100
μV
RMS
50
1
μF
Output Voltage Noise
e
n-LDO2
Minimum Output Capacitor
C
LDO(MIN)
Digital I/O Electrical Specifications (FLEN, EN)
Input High Threshold
Input Low Threshold
Input High Current
Input Low Current
V
IH
V
IL
I
IH
I
IL
V
IN
= 5.5V
V
IN
= 3.0V
V
IN
= 5.5V
V
IN
= 5.5V
-1
-1
1.6
0.4
+1
+1
V
V
μA
μA
I
2
C Interface
Interface complies with slave mode I
2
C interface as described by Philips I
2
C specification version 2.1 dated January, 2000.
V
B-IL
Digital Input Voltage
V
B-IH
SDA Output Low Level
Digital Input Current
Hysteresis of
Schmitt Trigger Inputs
Maximum Glitch Pulse
Rejection
I
B-IN
V
HYS
t
SP
I
DIN
(SDA) ≤ 3mA
-0.2
0.1
1.6
0.4
0.2
V
V
μA
V
0.4
V
50
ns
5
