RICHTEK RT9263CCX5, RT9263ECX5 Datasheet
Preliminary
RT9263
High Efficiency, Low Supply Current,
Step-up DC/DC Converter
General Description
The RT9263 is a compact, high efficient, step-up
DC/DC converter with an adaptive current mode
PWM control loop, providing a stable and high
efficient operation over a wide range of load
currents. It operates in both continuous and
discontinuous current modes in stable waveforms
without external compensation.
The low start-up input voltage below 1V makes
RT9263 suitable for 1 to 4 battery cell applications
providing up to 400mA output current. The 550KHz
high switching rate minimized the size of external
components. Besides, the 17µA low quiescent
current together with high efficiency maintains long
battery lifetime.
Ordering Information
RT9263
Package type
X5 : SOT89-5
Operating temperature range
C: Commercial standard
C : Chip enable control
E : Driver for external power devices
Typical Application Circuit
Features
z
1.0V Low Start-up Input Voltage
z
High Supply Capability to Deliver 3.3V 100mA
with 1V Input Voltage
z
17µµµµA Quiescent (Switch-off) Supply Current
z
90% Efficiency
z
550KHz Fixed Switching Rate
z
Providing Flexibility for Using Internal and
External Power Switches
z
SOT89-5 Package
Applications
PDA
z
Portable Instrument
z
DSC
z
Pin Configurations
Part Number Pin Configurations
321
321
TOP VIEW
1. CE
2. VDD
3. FB
4. LX
5. GND
TOP VIEW
1. EXT
2. VDD
3. FB
4. LX
5. GND
RT9263CCX5
(Plastic SOT89-5)
RT9263ECX5
(Plastic SOT89-5)
54
54
+
V
IN
VDD
CE
RT9263CCX5
GND FB
LX
100pF
R1
1.6M
R2
980K
L1
4.7µH
D1
1N5819
C2
1µF
+
C1
100µF
100µF
3.3V
V
OU T1
Fig. 1 RT9263CCX5 Typical Application for Portable Instruments below 400mA
DS9263-00 November 2001 www.richtek-ic.com.tw
1
RT9263
Preliminary
V
IN
3. 3/ 5V
V
+
VDD
RT9263ECX5
GND FB
100p F
LX
EXT
R1
1.6M
R2
980K
Q1
NMOS
L1
4.7µH
D1
1N58 19
C2
1µF
+
C1
100µF
100µF
3.3V
V
OU T1
Fig. 2 0.4A ~ 1A Output Current Application
L1
+
IN
100µF
VDD
RT9263ECX5
GND FB
10µH
EXT
LX
Q1
NMOS
0.1µF
Rm
0.05~0.1
D1
15V
V
+
OU T1
C1
100µF
R1
2.2M
R2
C2
200K
Ω
1µF
Fig. 3 High Voltage Application (Rm should be added when IL > 100mA)
3.3/5V
V
IN
Chip Ena bl e
+
100µF
VDD
RT9263CCX5
CE GND FB
L1
10µH
LX
Q1
NMOS
0.1µF
D1
R1
2.2M
R2
200K
C2
1µF
15V
V
+
C1
100µF
Fig.4 High Voltage Application with Shutdown Control
OU T1
www.richtek-ic.com.tw DS9263-00 November 2001
2
Function Block Diagram
Preliminary
RT9263
VDD
FB
CE
VDD
FB
1.25V
1. 25 V
RT9263CCX5
_
Loop Control Circuit
+
RT9263ECX5
_
Loop Control Circuit
+
LX
Q1
NMOS
R1
GND
EXT
LX
Q1
NMOS
R1
GND
DS9263-00 November 2001 www.richtek-ic.com.tw
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