RT9261B-32PB [RICHTEK]
VFM Step-Up DC/DC Converter;
| 型号： | RT9261B-32PB |
| 厂家： | 
RICHTEK TECHNOLOGY CORPORATION |
| 描述： | VFM Step-Up DC/DC Converter |
| 文件： | 总8页 (文件大小：127K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Preliminary
RT9261B
VFM Step-Up DC/DC Converter
General Description
Features
z Minimal Number of External Components (Only an
The RT9261B Series are VFM Step-up DC/DC converter
ICs with ultra low supply current by CMOS process and
suitable for use with battery-powered instruments.
Inductor, a Diode, and a Capacitor)
z Ultra Low Input Current (6.5μA at Switch Off)
z Capable of Supplying 50mA Output Current with
Internal Switch
The RT9261B IC consists of an oscillator, a VFM control
circuit, a driver transistor (LX switch), a reference voltage
unit, an error amplifier, resistors for voltage detection, and
a LX switch protection circuit.Alow ripple and high efficiency
step-up DC/DC converter can be constructed with the
RT9261B IC and only three external components.
z
2% Output Voltage Accuracy
z Low Ripple and Low Noise
z Low Start-up Voltage, 0.8V at 1mA
z 80% Efficiency with Low Cost Inductor
z +50 ppm/°C Low Temperature-Drift
z SOT-89 and SOT-23-5 Small Packages
z RoHS Compliant and 100% Lead (Pb)-Free
The EN pin enables the circuit to set the standby supply
current at a maximum of 0.5μA.
Ordering Information
RT9261B-
Applications
z Power source for battery-powered equipment
z Power source for cameras, camcorders, VCRs, PDAs,
pagers, electronic data banks, and hand-held
communication equipment
Package Type
B : SOT-23-5
X : SOT-89
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
z Power source for appliances, which require higher
voltage than that of batteries used in the appliances
Output Voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
Pin Configurations
(TOP VIEW)
EN
VOUT
NC
LX
1
2
3
5
Note :
RichTek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
4
GND
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
SOT-23-5
Marking Information
1
2
3
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
VOUT
(TAB)
GND
LX
SOT-89
DS9261B-12 March 2007
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1
Preliminary
RT9261B
Typical Application Circuit
D1
1N5819
L1
RT9261B
LX
VOUT
V
OUT
C
GND
OUT
V
IN
22uF
D1
1N5819
L1
RT9261B
LX
VOUT
V
OUT
OUT
C
V
EN
IN
GND
22uF
* L1 ranges from 27μH to 120μH
Functional Pin Description
Pin No.
Pin Name
Pin Function
-xxCX
-xxCB
1
2
4
2
5
1
3
GND
VOUT
LX
Ground
Output Voltage
3
Pin for Switching
Chip Enable (Active High)
No Connection
--
--
EN
NC
Function Block Diagram
V
Limiter
LX
LX
V
REF
LXSW
Buffer
VOUT
GND
-
+
OSC 190kHz
Error
Amplifier
Chip Enable
EN
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2
DS9261B-12 March 2007
Preliminary
RT9261B
Absolute Maximum Ratings
z Output Voltage -------------------------------------------------------------------------------------------------------- 8V
z LX Pin Voltage--------------------------------------------------------------------------------------------------------- 8V
z EN Pin Voltage(1) ------------------------------------------------------------------------------------------------------ −0.3 to VOUT +0.3V
z LX Pin Output Current ----------------------------------------------------------------------------------------------- 400mA
z Power Dissipation, PD @ TA = 25°C
SOT-89 ------------------------------------------------------------------------------------------------------------------ 0.5W
SOT-23-5 --------------------------------------------------------------------------------------------------------------- 0.25W
z Package Thermal Resistance
SOT-89, θJC ------------------------------------------------------------------------------------------------------------ 100°C/W
SOT-89, θJA ------------------------------------------------------------------------------------------------------------ 300°C/W
SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------- 250°C/W
z Operating Temperature Range ------------------------------------------------------------------------------------- −20 to +85°C
z Storage Temperature Range --------------------------------------------------------------------------------------- −65°C to 150°C
z Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------- 260°C
Notes: (1)Applicable to RT9261B-xxCB
Electrical Characteristics (Refer to Figure 1)
Parameter
Output Voltage Accuracy
Input Voltage
Symbol
Test Conditions
Min Typ Max Units
-2
--
--
--
+2
7
%
V
V
V
ΔV
OUT
V
V
V
IN
Start-up Voltage
Hold-on Voltage
V
--
0.8
--
1
I
I
= 1mA, V : 0 → 2V
ST
OUT
IN
0.7
--
--
= 1mA, V : 2 → 0V
HO
OUT
IN
≤ 3.5V (1)
24
36
36
45
OUT
To be measured at V in
IN
Input Current 1
μA
μA
3.5V < V
≤ 5V (2)
continuous switching
--
OUT
To be measured at V
switch off condition
in
Input Current 2 (1) (2)
--
6.5
10
OUT
--
--
18
20
36
45
V
≤ 3.5V (1)
OUT
To be measured at V in no
load (guaranteed by I1 and I2)
IN
Input Current 3
μA
3.5V < V
≤ 5V (2)
OUT
120
160
--
--
--
--
V
≤ 3.5V (1)
OUT
LX Switching Current
LX Leakage Current
mA
I
I
V
= 0.4V
= 6V
SWITCHING
LX
3.5V < V
≤ 5V (2)
OUT
--
--
0.5
V
V
V
μA
LEAKAGE
LX
140 190 240 kHz
140 190 320 kHz
= 2.5V to 5V
OUT
OUT
Maximum Oscillator Frequency
F
MAX
= 1.5V to 2.4V
Oscillator Duty Cycle
Efficiency
65
--
75
80
85
--
%
%
V
D
On (V “L”) side
OSC
LX
LX switch on
0.65 0.8
1.0
V
LX
Voltage Limit
Notes:
(1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and use External Circuit of Typical Application
(2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt= 25°C, and External Circuit of Typical Application
DS9261B-12 March 2007
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3
Preliminary
RT9261B
Electrical Characteristics (Refer to Figure 2)
Parameter
Output Voltage Accuracy
Input Voltage
Symbol
Test Conditions
Min
-2
Typ Max Units
--
--
+2
7
%
V
ΔV
OUT
--
V
V
V
IN
Start-up Voltage
Hold-on Voltage
Efficiency
--
0.8
--
1
V
I
I
= 1mA, V : 0 → 2V
ST
OUT
IN
0.7
--
V
= 1mA, V : 2 → 0V
HO
OUT
IN
--
--
--
80
24
36
--
%
V
≤ 3.5V (1)
36
45
OUT
To be measured at V in
IN
Input Current 1
μA
μA
3.5V < V
≤ 5V (2)
continuous switching
OUT
Input Current 2 (1) (2)
--
--
6.5
18
10
36
To be measured at V
OUT
in switch off condition
V
OUT
≤ 3.5V (1)
IN
To be measured at V in
Input Current 3
μA
no load (guaranteed by I1
and I2)
3.5V < V
≤ 5V (2)
--
20
--
45
--
OUT
V
≤ 3.5V (1)
120
160
--
OUT
LX Switching Current
mA
I
I
V
= 0.4V
SWITCHING
LX
3.5V < V
≤ 5V (2)
--
--
OUT
LX Leakage Current
EN “H” Level
--
0.5
V
= 6V
μA
V
LEAKAGE
LX
IN
IN
--
--
--
--
--
0.2
0.5
--
V
= VOUT * 0.9
= VOUT * 0.9
0.4×V
OUT
EN “L” Level
--
--
V
V
EN “H” Input Current
EN “ L” Input Current
EN = VOUT
EN = 0V
μA
μA
-0.5
140
140
65
190 240 kHz
190 320 kHz
V
V
= 2.5V to 5V
OUT
OUT
Maximum Oscillator Frequency
Oscillator Duty Cycle
F
MAX
= 1.5V to 2.4V
75
85
%
V
D
On (V “L”) side
OSC
LX
LX switch on
0.65
0.8
1.0
V
LX
Voltage Limit
Notes:
(1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and use External Circuit of Typical Application
(2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt= 25°C, and External Circuit of Typical Application
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4
DS9261B-12 March 2007
Preliminary
Typical Operating Characteristics
RT9261B
Start-up/Hold-on Voltage vs. Output Current
Output Voltage vs. Output Current
2.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.0V
2.5V
2
1.5
1
2.0V
1.5V
1.0V
Vstart
Vhold
0.5
0
VOUT = 3.3V
L = 47uH
VOUT
3.3V
=
0
30
60
90
120
150
180
0
50
100
150
200
Output Current (mA)
Output Current (mA)
Output Current vs. Ripple Voltage
Output Current vs. Ripple Voltage
300
250
200
150
100
50
90
80
70
60
50
40
30
20
10
0
2.5V
3.0V
2.0V
2.0V
3.0V
2.5V
1.5V
1.5V
VOUT = 3.3V
VOUT = 3.3V
COUT = 20uF
L = 47uH
COUT = 68uF
L = 47uH
1.0V
50
1.0V
50
0
0
100
150
200
0
100
150
200
Output Current (mA)
Output Current (mA)
Efficiency vs. output Current
Output Current vs. Ripple Voltage
90
80
70
60
50
40
30
20
10
0
25
20
15
10
5
3.0V
2.5V
2.0V
1.0V
2.5V
1.5V
3.0V
1.0V
VOUT = 3.3V
VOUT
3.3V
=
COUT = 170uF
L = 47uH
2.0V
1.5V
0
0
50
100
150
200
0
50
100
150
200
Output Current (mA)
Output Current (mA)
DS9261B-12 March 2007
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5
Preliminary
RT9261B
Start-up/Hold-on Voltage vs. Output Current
Output Voltage vs. Output Current
2.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.0V
2.5V
2
1.5V
2.0V
1.0V
1.5
1
Vstart
Vhold
0.5
0
VOUT
3.3V
=
VOUT
3.3V
=
0
20
40
60
80
100
120
0
50
100
150
200
Output Current (mA)
Output Current (mA)
Output Current vs. Ripple Voltage
Output Current vs. Ripple Voltage
300
250
200
150
100
50
90
80
70
60
50
40
30
20
10
0
2.0V
3.0V
2.5V
2.5V
3.0V
2.0V
VOUT = 3.3V
VOUT = 3.3V
1.0V
COUT = 20uF
L = 100uH
COUT = 68uF
L = 100uH
1.5V
1.5V
50
1.0V
50
0
0
100
150
200
0
100
150
200
Output Current (mA)
Output Current (mA)
Output Current vs. Ripple Voltage
Efficiency vs. output Current
100
90
80
70
60
50
40
30
20
10
0
18
16
14
12
10
8
2.5V
3.0V
2.5V
3.0V
2.0V
1.0V
2.0V
1.5V
1.0V
6
4
VOUT = 3.3V
COUT = 170uF
L = 100uH
VOUT
3.3V
=
2
1.5V
0
0
50
100
150
200
0
50
100
150
200
Output Current (mA)
Output Current (mA)
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6
DS9261B-12 March 2007
Preliminary
RT9261B
Outline Dimension
H
D
L
B
C
A
b
A1
e
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
A1
B
0.889
0.000
1.397
0.356
2.591
2.692
0.838
0.080
0.300
1.295
0.152
1.803
0.559
2.997
3.099
1.041
0.254
0.610
0.035
0.000
0.055
0.014
0.102
0.106
0.033
0.003
0.012
0.051
0.006
0.071
0.022
0.118
0.122
0.041
0.010
0.024
b
C
D
e
H
L
SOT-23-5 Surface Mount Package
DS9261B-12 March 2007
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7
Preliminary
RT9261B
D
D1
A
B
C
C1
e
e
H
A
b
b
b1
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
b
1.397
0.356
2.388
0.406
3.937
0.787
4.394
1.397
1.448
0.356
1.600
0.483
2.591
0.533
4.242
1.194
4.597
1.753
1.549
0.432
0.055
0.014
0.094
0.016
0.155
0.031
0.173
0.055
0.057
0.014
0.063
0.019
0.102
0.021
0.167
0.047
0.181
0.069
0.061
0.017
B
b1
C
C1
D
D1
e
H
3-Lead SOT-89 Surface Mount
Richtek Technology Corporation
Headquarter
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com
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8
DS9261B-12 March 2007
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