WL281E Low noise, High PSRR, High speed, CMOS LDO Http://www.willsemi.com Descriptions The WL281E series is a high accuracy, low noise, high speed, low dropout CMOS Linear regulator with high ripple rejection. The devices offer a new level of cost effective performance in cellular phones, laptop and notebook computers, and other portable devices. The current limiter's fold-back circuit also operates as a short circuit protection and an output current limiter at the output pin. The WL281E regulators are available in standard SOT-23-5L packages. Standard products are Pb-free and Halogen-free. Features Input voltage : 2.7V~5.5V Output range : 1.2V~3.3V Output current : 2mA (Up to 3mA Typ.) PSRR : 75dB @ 217Hz Dropout voltage : 17mV @ UT =2mA Quiescent current : 7 A Typ. Shut-down current : <.1 A Recommend capacitor : 1uF Applications SOT-23-5L VOUT NC 5 4 1 2 3 VIN GND EN Pin Configuration (Top View) **** MP3/MP4 Players Cellphones, radiophone, digital cameras Bluetooth, wireless handsets Others portable electronics device For detail marking information, please see page 9. Marking Order Information For detail order information, please see page 9. Will Semiconductor Ltd. 1 Dec. 211 Rev.3.
Typical Application Pin Description WL281E PIN Symbol Description VIN 1uF ON 1 5 2 3 4 1uF VOUT 1 VIN Input 2 GND Ground 3 EN Enable (Active high) 4 NC Not connected 5 VOUT Output OFF Block Diagram Will Semiconductor Ltd. 2 Dec. 211 Rev.3.
Absolute Maximum Ratings Parameter Value Unit Power Dissipation Internal limited mw V IN Range -.3 6.5 V V EN Range -.3 V IN V Range -.3 V IN V Lead Temperature Range 26 Storage Temperature Range -55 ~ 15 Operating Junction Temperature Range 15 o C o C o C Recommend Operating Ratings Parameter Value Unit Operating Supply voltage 2.7 5.5 V Operating Temperature Range -4 85 Thermal Resistance, R JA 25 o C o C/W Electronics Characteristics (Ta=25 o C, V IN = +1V, C IN =C OUT =1uF, unless otherwise noted) Parameter Symbol Condition Min. Typ. Max. Unit <2V, V IN =2.7V, UT =1mA Output Voltage 2V, UT=1mA.97.98 Ref. to Output Voltage vs. Current Limit I LIM V EN =V IN Output Current Chart Dropout Voltage V DROP 3 2 =2.8V, UT =2mA 17 2 =2.8V, UT =3mA 25 3 Line Regulation V LINE V IN =2.7~5.5V, UT =1mA 1.15 %/V Load Regulation V Load =2.8V, UT =1~3mA 2 3 mv Quiescent Current I Q =2.8V, UT = 7 1 A V EN =V IN, Short Current I SHORT Short to GND with 1 17 ma Shut-down Current I SHDN V EN =V.1 A Power Supply Rejection Rate PSRR V IN =( +1V) DC +.5V P-P F=217Hz,Iout=1mA 75 V IN =( +1V) DC +.5V P-P F=1KHz, Iout=1mA 65 db EN logic high voltage V ENH V IN =5.5V, UT =1mA 1.2 V EN logic low voltage V ENL V IN =5.5V, =V.4 V EN Input Current I EN V EN = to 5.5V A Output Noise Voltage e NO 1Hz to 1KHz, C OUT =1 F 1 V RMS V ma mv Will Semiconductor Ltd. 3 Dec. 211 Rev.3.
Typical characteristics (Ta=25 o C, V IN = +1V, C IN =C OUT =1uF, unless otherwise noted) 9 8 8 7 Quiescent Current (ua) 7 6 5 4 3 2 1 =2.8V =ma Quiescent Current(uA) 6 5 4 3 2 1 =1.2V =ma.5 1.5 2. 2.5 3. 3.5 4. 4.5 5. 5.5 Input Voltage (V) Quiescent current vs. Supply voltage.5 1.5 2. 2.5 3. 3.5 4. 4.5 5. 5.5 Input Voltage(V) Quiescent current vs. Supply voltage Output Voltage(V) 3. 2.5 2. 1.5.5 3. 2.75 2.5 2.25 2. 1.75 =1mA 1.5 1.25 =2mA.75.5.25.5 1.5 2. 2.5 3. 3.5 4. 4.5 5. 5.5 Input Voltage(V) Output voltage vs. Supply voltage = -4 o C VIN = 3.8V 2 4 6 8 1 12 14 Output Voltage(V) 1.4 1.2.8.6.4.2 =1mA =2mA.5 1.5 2. 2.5 3. 3.5 4. 4.5 5. 5.5 1.4 1.2.8.6 Input Voltage(V) Output voltage vs. Supply voltage = -4 o C.4 VIN = 2.7V.2 1 2 3 4 5 6 7 Will Semiconductor Ltd. 4 Dec. 211 Rev.3.
3. 2.5 = 25 o C 1.4 1.2 = 25 o C 2. 1.5.5 2 4 6 8 1 12 14 VIN = 3.8V.8.6.4 VIN = 2.7V.2 1 2 3 4 5 3. 2.5 = 85 o C 1.4 1.2 = 85 o C 2. 1.5 VIN = 3.8V.5 2 4 6 8 1 12 14 PSRR(dB) 1 9 8 7 6 5 4 3 2 1 V IN = 3.8V+.5V P-P = 2.8V UT = 1mA 1 1 1 1 Frequency(HZ) PSRR PSRR(dB).8.6.4.2 1 2 3 4 5 1 9 8 7 6 5 4 PSRR VIN = 2.7V 3 V IN = 3.V+.5V P-P 2 = 1.2V 1 UT = 1mA 1 1 1 1 Frequency(HZ) Will Semiconductor Ltd. 5 Dec. 211 Rev.3.
3.1 3 3. 25 2.9 2.8 2.7 VDROP(mV) 2 15 1 2.6 V IN = 3.8V UT = 1mA 5 =2.8V 2.5-5 -25 25 5 75 1 125 15 5 1 15 2 25 3 Temperature (C O ) Output Current(mA) Output voltage vs. Temperature Output voltage vs. Temperature Start Up Start Up Shutdown Shutdown Will Semiconductor Ltd. 6 Dec. 211 Rev.3.
Load Step Load Step Line Step Line Step Will Semiconductor Ltd. 7 Dec. 211 Rev.3.
Packaging Information SOT-23-5L WL281E Symbol Dimensions In Millimeters Min. Typ. Max. A 5-1.25 A1 -.1 A2 5-1.15 b.3.4.5 c.1 -.2 D 2.82 2.9 3.2 E 1.5 1.6 1.7 E1 2.65 2.8 2.95 e.95 (Basic) e1 1.8 1.9 2. L.3.45.6 o - 8 o Will Semiconductor Ltd. 8 Dec. 211 Rev.3.
ORDER INFORMATION Ordering No. Vout Operating Package (V) Temperature WL281E12-5/TR 1.2 SOT-23-5L -4~+85 C WL281E13-5/TR 1.3 SOT-23-5L -4~+85 C WL281E15-5/TR 1.5 SOT-23-5L -4~+85 C WL281E18-5/TR 1.8 SOT-23-5L -4~+85 C WL281E25-5/TR 2.5 SOT-23-5L -4~+85 C WL281E28-5/TR 2.8 SOT-23-5L -4~+85 C WL281E3-5/TR 3. SOT-23-5L -4~+85 C WL281E33-5/TR 3.3 SOT-23-5L -4~+85 C Marking WE12 WE13 WE15 WE18 WE25 WE28 WE3 WE33 Shipping Marking: WE** YY WW = Device Code = Year = Week Will Semiconductor Ltd. 9 Dec. 211 Rev.3.