SP1938 - Sync Power Corp.

SP1938
DC-DC Step-Up Converter for White LED
DESCRIPTION
The SP1938 is a step-up DC/DC converter for white
LED driver with over voltage protection. The device
can driver one to four LEDs in series from a single cell
Lithium Ion battery.
Internal functions include current limiting; thermal
shutdown; OVP and soft-start to prevent damage
operate status. The SP1938 operates at 0.8MHz
apply to Lithium-Ion powered systems. A low 95mV
reference voltage minimizes power loss in the current
setting resistor for better efficiency.
The SP1938 is available in small package SOT-23-6L.
APPLICATIONS
 Battery Power Equipment
 Notebook Computers
 PDA
 Cellular Phone
FEATURES
 Current Source with Over Voltage Protection
 Fast 0.8MHz Switching Frequency
 High Efficiency up to 87%
 Drives up to Four LEDs From 3.2V Supply
 Drives up to Six LEDs From a 5V Supply
 Low Quiescent Current
 Disconnects LEDs in Shutdown Mode
 Internal Over Temperature and Current Limiting
Shutdown Function
 Internal Soft-Start Circuit
 26V Rugged Bipolar Switch

Available in a Small SOT-23-6L Package
PINCONFIGURATION(SOT-23-6L)
2015/03/15 Ver.5
PART MARKING
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SP1938
DC-DC Step-Up Converter for White LED
TYPICALAPPLCATION CIRCUIT
PIN DESCRIPTION
Pin
1
2
3
4
5
6
Symbol
SW
GND
FB
SHDN
OVP
VIN
Description
Connect inductor/diode here
Ground Pin
Connect cathode of lowest LED and resistor here
Combined active low enable and PWM control pin for LED dimming
Over voltage Protection and Connect to the output capacitor of the Converter
Supply Voltage Input
ORDERINGINFORMATION
Part Number
Package
SP1938S26RGB
SOT-23-6L
※ Week Code : A ~ Z( 1 ~ 26 ) ; a ~ z( 27 ~ 52 )
※ SP1938S26RGB : Tape Reel ; Pb – Free ; Halogen -Free
2015/03/15 Ver.5
Part
Marking
98YW
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SP1938
DC-DC Step-Up Converter for White LED
BLOCK DIAGRAM
ABSOULTE MAXIMUM RATINGS
(TA=25℃ Unless otherwise specified)
Parameter
DC Supply Voltage
SW Voltage
FB Voltage
SHDN Voltage
Operating Temperature
Maximum Junction Temperature
Storage Temperature
Symbol
VIN
VSW
Value
10
26
Unit
V
V
VFB
10
10
-40~85
125
-65~150
V
V
℃
℃
℃
VSHDN
TOPR
TJ(Max)
TS
The IC has a protection circuit against static electricity. Do not apply high static electricity or high voltage that
exceeds the performance of the protection circuit to the IC.
2015/03/15 Ver.5
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SP1938
DC-DC Step-Up Converter for White LED
ELECTRICAL CHARACTERISTICS
(TA=25℃, VIN=3V, VSHDN=3V, Unless otherwise specified)
Parameter
Operating Voltage
Feedback Voltage
FB Pin Bias Current
Supply Current
Conditions
ISW=100mA, Duty Cycle = 66%
Min.
2.5
86
VSHDN = 0V
Switching Frequency
Maximum Duty Cycle
Switch Current Limit
Switch Leakage Current
Switch Saturation Voltage
SHDN Voltage High
SHDN Voltage Low
SHDN Pin Current
Over Voltage Protection
2015/03/15 Ver.5
0.8
Vsw= 5V
Isw = 200mA
Typ.
2.8
0.05
1.2
85
320
0.01
150
Max.
9
110
150
3.5
1.0
1.6
5
1.5
0.4
90
VOUT rising
18.4
Unit
V
mV
nA
mA
μA
MHz
%
mA
μA
mV
V
V
uA
V
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SP1938
DC-DC Step-Up Converter for White LED
APPLICATION CIRCUIT
2015/03/15 Ver.5
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SP1938
DC-DC Step-Up Converter for White LED
SOT-23-6L PACKAGE OUTLINE
2015/03/15 Ver.5
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SP1938
DC-DC Step-Up Converter for White LED
Information provided is alleged to be exact and consistent. SYNC Power Corporation presumes no responsibility for the
penalties of use of such information or for any violation of patents or other rights of third parties which may result from its use.
No license is granted by allegation or otherwise under any patent or patent rights of SYNC Power Corporation. Conditions
mentioned in this publication are subject to change without notice. This publication surpasses and replaces all information
previously supplied. SYNC Power Corporation products are not authorized for use as critical components in life support
devices or systems without express written approval of SYNC Power Corporation.
© The SYNC Power logo is a registered trademark of SYNC Power Corporation
© 2004 SYNC Power Corporation – Printed in Taiwan – All Rights Reserved
SYNC Power Corporation
7F-2, No.3-1, Park Street
NanKang District (NKSP), Taipei, Taiwan 115
Phone: 886-2-2655-8178
Fax: 886-2-2655-8468
http://www.syncpower.com
2015/03/15 Ver.5
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