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Details, datasheet, quote on part number:RT9261B-26CX
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| Part: | RT9261B-26CX |
| Category: | Power Management => DC-DC Converters => Step-up => Switching |
| Description: | Input Volt. Range(V) = 0.85~7 ;; Output Volt. Range(V) = 1.5~5.0 ;; Quiescent Current = 10 ga ;; Frequency(kHz) = 140~240 ;; Eff.(%)Max. = 75 ;; Internal Switch = V ;; External Switch = ;; Chip Enable = V ;; LDO Built-in = ;; V Detect Built-in = ;; Packages = SOT-25, SOT-89 ;; |
| Company: | RichTek Technology |
| Datasheet: | Download RT9261B-26CX datasheet File size : 182 kB |
| Request For quote: | Find where to buy RT9261B-26CX
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Datasheet text preview:
Preliminary
RT9261B
VFM Step-up DC/DC Converter
General Description
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. 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. A low ripple and high efficiency step-up DC/DC converter can be constructed with the RT9261B IC and only three external components. The CE pin enables the circuit to set the standby supply current at a maximum of 0.5µA.
eatures
Minimal Number of External Components (Only an Inductor, a Diode, and a Capacitor) Ultra Low Input Current (6.5µA at Switch Off) Capable of Supplying 50mA Output Current with Internal Switch ±2% Output Voltage Accuracy Low Ripple and Low Noise Low Start-up Voltage, 0.8V at 1mA 80% Efficiency with Low Cost Inductor +50 ppm/°C Low Temperature-Drift SOT-89 and SOT-25 Small Packages
Applications
Power source for battery-powered equipment Power source for cameras, camcorders, VCRs, PDAs, pagers, electronic data banks, and handheld communication equipment F Power source for appliances, which require higher voltage than that of batteries used in the appliances
Ordering Information
RT9261BPackage type B : SOT-25 X : SOT-89 Operating temperature range C: Commercial standard Output voltage 15 : 1.5V 16 : 1.6V : 49 : 4.9V 50 : 5.0V
Pin Configurations
Part Number RT9261BCX (Plastic SOT-89)
1 2 3
Pin Configurations
TOP VIEW 1. GND 2. VOUT (TAB) 3. LX TOP VIEW
5 4
RT9261BCB (Plastic SOT-25)
1
2
3
1. 2. 3. 4.
CE VOUT NC GND 5. LX
DS9261B-03 September 2001
www.richtek.com
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RT9261B
Typical Application Circuit
Preliminary
D1 L1 VIN 27µH 1N5819 RT9261B LX VOUT GND VOU T +
-
Co 22µF
D1 L1 VIN 27µH 1N5819 RT9261B LX VOUT CE GND
VOU T + Co - 22µF
* L1 ranges from 27µH to 120µH
Pin Description
Pin No. -xxCX 1 2 3 ---xxCB 4 2 5 1 3 Pin Name GND VOUT LX CE NC Ground Output Voltage Pin for Switching Chip Enable (Active High) No Connection Pin Function
Function Block Diagram
LX LXSW Buffer GND VFM Control OSC 190kHz Chip Enable + Error Amp. VOUT VLX Limiter Vref
CE
www.richtek.com
DS9261B-03 September 2001
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Preliminary Absolute Maximum Ratings
Output Voltage LX Pin Voltage (1) CE Pin Voltage LX Pin Output Current Power Dissipation, PD @ TA = 25°C SOT-89 SOT-25 Package Thermal Resistance SOT-89, JC SOT-89, JA SOT-25, JA Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) Notes: (1) Applicable to RT9261B-xxCB
RT9261B
8V 8V -0.3 to VOUT +0.3V 400mA 0.5W 0.25W 100°C/W 300°C/W 250°C/W -20 to +85°C -65°C to 150°C 260°C
Electrical Characteristics (Refer to Fig. 1)
Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Hold-on Voltage Input Current 1
(1) (2)
Symbol VOUT VIN VST VHO
Test Conditions
Min -2 --
Typ --0.8 -24 36 6.5 18 20 ---190 75 80 0.8
Max Units +2 7 1 -36 45 10 36 45 --0.5 240 85 -1.0 % V V V µA µA
IOUT = 1mA, VIN: 0 2V IOUT = 1mA, VIN: 2 0V To be measured at VIN in continuous switching To be measured at VOUT in switch off condition
-0.7 -----120 160 -140 65 -0.65
VOUT 3.5V
(1) (2)
3.5V < VOUT 5V
Input Current 2
Input Current 3
VOUT 3.5V
(1) (2)
3.5V < VOUT 5V LX Switching Current LX Leakage Current Maximum Oscillator Frequency Oscillator Duty Cycle Efficiency VLX Voltage Limit VOUT 3.5V
(1)
To be measured at VIN in no load (guaranteed by I1 and I2) ISWITCHING VLX = 0.4V ILEAKAGE FMAX DOSC On (VLX "L") side LX switch on VLX = 6V
µA
3.5V < VOUT 5V
(2)
mA µA KHz % % V
Notes: (1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and External Circuit of Typical Application (2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and External Circuit of Typical Application
DS9261B-03 September 2001
www.richtek.com
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