RICHTEK RT9261-38CX

RT9261/A
Preliminary
VFM Step-up DC/DC Converter
General Description
Features
The RT9261 Series are VFM Step-up DC/DC ICs
z
with ultra low supply current by CMOS process and
suitable for use with battery-powered instruments.
Minimal Number of External Components ( Only
an inductor, a diode, and a capacitor)
z
Ultra Low Input Current ( 5µ
µA at Switch Off)
The RT9261 IC consists of an oscillator, a VFM
z
± 2% High Output Voltage Accuracy
Low Ripple and Low Noise
control circuit, a driver transistor (LX switch), a
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Low Start-up Voltage, 0.85V at 1mA
reference voltage unit, an error amplifier, resistors for
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75% Efficiency with Low Cost Inductor
voltage detection, and a LX switch protection circuit.
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A low ripple and high efficiency step-up DC/DC
+50 ppm/°°C Low Temperature-Drift
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SOT-89 and SOT-25 Small Packages
z
converter can be constructed of this RT9261 IC with
only three external components.
The RT9261A IC provides with a drive pin (EXT) for
an external transistor, so that a power transistor can
Applications
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Power source for battery-powered equipment
z
Power source for cameras, camcorders, VCRs,
PDAs, pagers, electronic data banks, and hand-
be externally applied. Therefore, the RT9261A IC is
recommended for applications where large currents
are required. CE pin enables circuit to set the
standby supply current at a maximum of 0.5µA.
Ordering Information
RT9261A-…… … …
held communication equipment
z
Power source for applications, which require
higher voltage than that of batteries used in the
appliances
Pin Configurations
Part Number
Package type
B : SOT-25
X : SOT-89
TOP VIEW
RT9261-……CX
1
2
3
TOP VIEW
RT9261A-……CX
1. GND
2. VOUT (TAB)
3. EXT
(Plastic SOT-89)
1
RT9261-……CB
(Plastic SOT-25)
A : Use external switch
Use internal switch
(Plastic SOT-25)
2
3
TOP VIEW
5
1
RT9261A-……CB
4
2
3
1.
2.
3.
4.
5.
CE
VOUT
NC
GND
LX
TOP VIEW
5
1
DS9261/A-03 January 2002
1. GND
2. VOUT (TAB)
3. LX
(Plastic SOT-89)
Operating temperature range
C: Commercial standard
Output voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
Pin Configurations
4
2
3
1.
2.
3.
4.
5.
CE
VOUT
NC
GND
EXT
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RT9261/A
Preliminary
Absolute Maximum Ratings
z
z
z
Output Voltage
LX Pin Voltage
8V
(1)
EXT Pin Voltage
8V
(2)
-0.3 to VOUT +0.3V
(3)
z
CE Pin Voltage
z
LX Pin Output Current
-0.3 to VOUT +0.3V
(1)
250mA
(2)
z
EXT Pin Current
z
Power Dissipation, PD @ TA = 25°C
z
SOT-89
0.5W
SOT-25
0.25W
z
±50mA
Package Thermal Resistance
SOT-89, θJC
100°C/W
SOT-89, θJA
300°C/W
SOT-25, θJA
250°C/W
z
Operating Temperature Range
-20 to +85°C
z
Storage Temperature Range
165°C
z
Lead Temperature (Soldering, 10 sec.)
260°C
Notes:
(1) Applicable to RT9261-……CX and RT9261-……CB
(2) Applicable to RT9261A-……CX and RT9261A-……CB
(3) Applicable to RT9261-……CB and RT9261A-……CB
Electrical Characteristics (Refer to Fig. 1)
Parameter
Symbol
Test Conditions
Min
Typ
Max Units
Output Voltage Accuracy
∆VOUT
-2
--
+2
%
Input Voltage
VIN
--
--
7
V
Start-up Voltage
VST
IOUT = 1mA, VIN: 0 → 2V
--
0.85
1.0
V
VHO
IOUT = 1mA, VIN: 2 → 0V
0.7
--
--
V
To be measured at VIN at
no load
--
15
18
--
18
24
--
5
8
60
--
--
80
--
--
--
--
0.5
µA
80
120
160
KHz
65
75
85
%
--
75
--
%
0.65
0.8
1.0
V
Hold-on Voltage
Input Current 1
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
(2)
To be measured at VOUT
in switch off condition
Input Current 2
LX Switching Current
VOUT ≤ 3.5V
(1)
ISWITCHING
VLX = 0.4V
LX Leakage Current
ILEAKAGE
VLX = 6V
Maximum Oscillator
FMAX
Oscillator Duty Cycle
DOSC
3.5V < VOUT ≤ 5V
(2)
On ( VLX ” L ” ) side
Efficiency
VLX Voltage Limit
LX switch on
µA
µA
mA
Notes:
(1) VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application
(2) VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application
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DS9261/A-03 January 2002
RT9261/A
Preliminary
Electrical Characteristics (Refer to Fig. 2)
Parameter
Symbol
Test Conditions
Min
Typ
Max Units
Output Voltage Accuracy
∆VOUT
-2
--
+2
%
Input Voltage
VIN
--
--
7
V
Start-up Voltage
VST
IOUT = 1mA, VIN : 0 → 2V
--
0.85
1.0
V
To be measured at VIN at no
load
--
30
50
(2)
--
60
90
(2)
To be measured at VOUT in
switch off condition
--
6
10
VEXT = VOUT – 0.4V
-1.5
--
--
(2)
-2
--
--
VEXT = 0.4V
1.5
--
--
(2)
2
--
--
80
120
160
KHz
65
75
85
%
Input Current 1
Input Current 2
EXT “H” Output
Current
EXT “L” Output
Current
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
Maximum Oscillator Frequency
FMAX
Oscillator Duty Cycle
DOSC
VEXT ” H ” side
µA
µA
mA
mA
Notes:
(1) Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of
Typical Application
(2) Unless otherwise provided, VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical
Application
DS9261/A-03 January 2002
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RT9261/A
Preliminary
Electrical Characteristics (Refer to Fig. 3)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Output Voltage Accuracy
∆VOUT
-2
--
+2
%
Input Voltage
VIN
--
--
7
V
Start-up Voltage
VST
IOUT = 1mA, VIN : 0 → 2V
--
0.85
1.0
V
VHO
IOUT = 1mA, VIN : 2 → 0V
0.7
--
--
V
--
75
--
--
85
--
Hold-on Voltage
Efficiency
Input Current 1
Input Current 2
LX Switching
Current
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
To be measured at VIN at
no load
--
15
18
--
18
24
To be measured at VOUT
in switch off condition
--
5
8
(2)
--
6
10
60
--
--
80
--
--
--
--
0.5
µA
(1)
3.5V < VOUT ≤ 5V
LX Leakage Current
%
(2)
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(2)
(2)
ISWITCHING
VLX = 0.4V
ILEAKAGE
VLX = 6V
µA
µA
mA
CE “H” Level
VIN = VOUT × 0.9
0.4× VOUT
--
--
V
CE “ L” Level
VIN = VOUT × 0.9
--
--
0.2
V
CE “ H” Input Current
CE = VOUT
--
--
0.5
µA
CE “ L“ Input Current
CE = 0V
-0.5
--
--
µA
80
120
160
KHz
65
75
85
%
0.65
0.8
1.0
V
Maximum Oscillator Frequency
FMAX
Oscillator Duty Cycle
DOSC
VLX Voltage Limit
On (VLX ” L” ) side
LX switch on
Notes:
(1) Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of
Typical Application
(2) Unless otherwise provided, VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical
Application
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DS9261/A-03 January 2002
RT9261/A
Preliminary
Electrical Characteristics (Refer to Fig. 4)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Output Voltage Accuracy
∆VOUT
-2
--
+2
%
Input Voltage
VIN
--
--
7
V
Start-up Voltage
VST
--
0.85
1.0
V
--
75
--
--
85
--
--
30
50
--
60
90
--
6
10
-1.5
--
--
-2
--
--
1.5
--
--
2
--
--
Efficiency
Input Current 1
Input Current 2
EXT “H” Output
Current
EXT “L” Output
Current
VOUT ≤ 3.5V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
To be measured at VIN at
no load
(2)
To be measured at VOUT in
switch off condition
(2)
VEXT = VOUT – 0.4V
(2)
VEXT = 0.4V
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(2)
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
(2)
(1)
3.5V < VOUT ≤ 5V
VOUT ≤ 3.5V
IOUT = 1mA, VIN : 0 → 2V
(1)
3.5V < VOUT ≤ 5V
%
µA
µA
mA
mA
CE “H” Level
VIN = VOUT × 0.9
0.4× VOUT
--
--
V
CE “ L” Level
VIN = VOUT × 0.9
--
--
0.2
V
CE “ H” Input Current
CE = VOUT
--
--
0.5
µA
CE “ L“ Input Current
CE = 0V
-0.5
--
--
µA
80
120
160
KHz
65
75
85
%
0.65
0.8
1.0
V
Maximum Oscillator Frequency
FMAX
Oscillator Duty Cycle
DOSC
VLX Voltage Limit
On (VLX ” L” ) side
LX switch on
Notes:
(1) Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of
Typical Application
(2) Unless otherwise provided, VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical
Application
DS9261/A-03 January 2002
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RT9261/A
Preliminary
Function Block Diagram
VLX Limiter
LX
Vref
LXSW
VOUT
Buffer
GND
_
VFM Control
+
Error Amp.
OSC 100kHz
EXT
Chip Enable
CE
Notes:
(1) LX Pin .……
only for 9261-……CX and 9261-……CB
(2) EXT Pin ……
only for 9261A-……CX and 9261A-……CB
(3) CE Pin ……
only for 9261-……CB and 9261A-……CB
Pin Description
Pin No.
Pin Name
Pin Function
4
GND
Ground
2
2
VOUT
Output Voltage
--
5
--
LX
Pin for Switching
--
3
--
5
EXT
Drive External Device
--
--
1
1
CE
Chip Enable (Active High)
--
--
3
3
NC
No Connected
-xxCX
A-xxCX
-xxCB
A-xxCB
1
1
4
2
2
3
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DS9261/A-03 January 2002
RT9261/A
Preliminary
Typical Application Circuit
D1
1N5819
L1
RT9261CX
LX
VOUT
100µH
GND
VOUT
+ Co
_ 22µF
VIN
Fig. 1
L1
D1
27µH
VIN
0.01µF
Cb
ZTX
650
1N5819
RT9261ACX
EXT
VOUT
GND
Tr
Rb
300Ω
VOUT
+ Co
_ 22µF
Fig. 2
D1
L1
100µH
VIN
1N5819
LX
NC
RT9261CB
EXT
VOUT
VOUT
CE GND
+ Co
_ 22µF
Fig. 3
DS9261/A-03 January 2002
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RT9261/A
Preliminary
L1
D1
27µH
0.01µF NC
Cb
1N5819
RT9261ACB
LX
EXT
VIN
ZTX
650
CE
VOUT
GND
Rb
Tr 300Ω
VOUT
+ Co
_ 22µF
Fig. 4
D1
L1
27µH
VIN
1N5819
RT9261CB
LX
NC
EXT
CE
CE GND
VOUT
VOUT
+ Co
_ 22µF
Fig. 5
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DS9261/A-03 January 2002
RT9261/A
Preliminary
Typical Operating Charateristics
RT9261(2.7V)
Output Current vs. Ripple Voltage
1.4
120
1.2
Ripple Voltage (mV p-p)
Start-up/Hold-on Voltage Vstart/Vhold (V)
RT9261(2.7V)
Start-up/Hold-on Voltage vs. Output Current
Vstart
1.0
0.8
Vhold
0.6
0.4
0.2
100
2.0V
60
40
0.9V
RT9261
VOUT = 2.7V
0
0
10
20
30
40
50
0
Output Current (mA)
3.0
0.9V
2.0
1.5
1.0
0.5
RT9261
VOUT = 2.7V
0.0
0
20
40
60
80
2.75
2.70
2.65
RT9261
VOUT = 2.7V
2.60
-40
100
-20
2.0V
40
60
80
Supply Current vs. Temperature
RT9261
VOUT = 2.7V
60
Supply Current (µ A)
2.5V
1.5V
0.9V
20
70
80
60
0
Temperature (° C)
RT9261(2.7V)
Efficiency vs. Output Current
70
100
2.80
Output Current (mA)
90
80
2.85
Output Voltage (V)
Output Voltage (V)
2.5
60
Output Voltage vs. Temperature
2.0V
1.5V
40
2.90
2.5V
1.0V
20
Output Current (mA)
RT9261(2.7V)
Output Voltage vs. Output Current
Efficiency (%)
2.5V
1.5V
20
RT9261
VOUT = 2.7V
0.0
80
1.0V
50
40
30
20
50
40
30
20
Input Current 2
RT9261
VOUT = 2.7V
10
0
0
20
40
60
Output Current (mA)
DS9261/A-03 January 2002
80
100
10
Input Current 1
0
-40
-20
0
20
40
60
80
Temperature (° C)
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RT9261/A
Preliminary
RT9261A (2.7V)
Output Voltage vs. Output Current
3.0
140
2.5V
1.5V
2.5
120
Output Voltage (V)
Maximum Oscillator Frequency (kHz)
Maximum Oscillator Frequency vs. Temp.
160
100
80
60
1.0V
0.9V
2.0
1.5
1.0
40
0.5
RT9261
VOUT = 2.7V
20
-20
0
20
40
Temperature ( ° C)
60
RT9261A
VOUT = 2.7V
0.0
0
-40
0
80
30
60
90
120
RT9261A (2.7V)
Efficiency vs. Output Current
100
80
2.5V
90
60
Efficiency (%)
Oscillator Duty Cycle (%)
70
80
70
2.0V
0.9V
50
1.0V
1.5V
40
30
20
60
RT9261
VOUT = 2.7V
50
-40
-20
0
20
40
60
RT9261A
VOUT = 2.7V
10
0
0
80
30
Temperature ( °C)
60
90
120
150
Output Current (mA)
RT9261A (2.7V)
Output Current vs. Ripple Voltage
Start-up/Hold-on Voltage vs. Output Current
1.6
120
1.4
1.2
Ripple Voltage (mV p-p)
Start-up/Hold-on Voltage Vstart/Vhold (V)
150
Output Current (mA)
Oscillator Duty Cycle vs. Temperatrue
Vstart
1.0
0.8
Vhold
0.6
0.4
RT9261A
VOUT = 2.7V
0.2
0.0
0
30
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10
2.0V
60
90
Output Current (mA)
120
150
100
2.5V
80
2.0V
60
1.5V
40
0.9V
RT9261A
VOUT = 2.7V
20
0
0
30
60
90
120
150
Output Current (mA)
DS9261/A-03 January 2002
RT9261/A
Preliminary
Package Information
D
A
D1
H
B
C
C1
e
e
A
b
Symbol
b1
b
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
1.397
1.600
0.055
0.063
b
0.356
0.483
0.014
0.019
B
2.388
2.591
0.094
0.102
b1
0.406
0.533
0.016
0.021
C
--
4.242
--
0.167
C1
0.787
1.194
0.031
0.047
D
4.394
4.597
0.173
0.181
D1
1.397
1.753
0.055
0.069
e
1.448
1.549
0.057
0.061
H
0.355
0.432
0.014
0.017
3-Lead SOT-89 Surface Mount
DS9261/A-03 January 2002
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11
RT9261/A
Preliminary
D
5
4
C
B
1
b
3
H
A
e
Symbol
L
A1
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.889
1.295
0.035
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.356
0.559
0.014
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.102
0.254
0.004
0.010
L
0.356
0.610
0.014
0.024
SOT- 25 Surface Mount Package
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DS9261/A-03 January 2002
Preliminary
DS9261/A-03 January 2002
RT9261/A
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RT9261/A
Preliminary
RICHTEK TECHNOLOGY CORP.
RICHTEK TECHNOLOGY CORP.
Headquarter
Taipei Office (Marketing)
6F, No. 35, Hsintai Road, Chupei City
8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5510047 Fax: (8863)5537749
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek-ic.com.tw
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14
DS9261/A-03 January 2002