Datasheet US1205-36CL, US1205-33CL, US1205-30CL, US1205-25CL, US1205CL Datasheet (UNISEM)

Page 1
US1205
300 mA LOW DROPOUT POSITIVE
ADJUSTABLE REGULATOR
PRELIMINARY DATASHEET
FEATURESFEATURES
SOT23 package Stable with 2.2uF ceramic capacitor 1% Voltage Reference Accuracy Only 270mV Dropout at 300 mA
170mV Dropout at 150mA 10nA Quiescent Current in Shutdown Current Limit and Thermal Shutdown Logic input Enable pin
APPLICATIONSAPPLICATIONS
Laptop, Notebook & Palmtop computers Battery powered Equipments PCMCIA Vcc & Vpp regulator Concumer Electronics High Efficiency Linear Power Supplies
TYPICAL APPLICATIONTYPICAL APPLICATION
Vin Vout
C1
2.2uF
S.D.
Enable
Vin
1
Gnd
2
En
3 4
Vout
Adj
DESCRIPTIONDESCRIPTION
The US1205 device is an efficient linear voltage regula­tor with better than 1% initial voltage accuracy, very low dropout voltage and very low ground current designed especially for hand held, battery powered applications. Other features of the device are; TTL compatible enable/ shutdown control input, current limiting and thermal shutdown. The US1205 is available in fixed and adjustable output voltage versions in a small SOT23-5 package.
5
R1
Vo=1.242 X (1+R1/R2)
C2
R2
2.2uF
1205app1-1.1
Typical application of the US1205 ajustable.
3.3V 2.5V
C1
2.2uF
S.D. Enable
Vin
1
Gnd
2
En
3 4
Vout
Byp
5
C2
2.2uF
1205app2-1.2
C3 1000pF
Typical application of the US1205 Fixed voltage.
PACKAGE ORDER INFORMATIONPACKAGE ORDER INFORMATION
Tj (°C) 5 LEAD SOT23 Output SOT 23 Marking Voltage
0 TO 125 US1205CL AT00 Adj 0 TO 125 US1205-25CL AT25 2.5 V 0 TO 125 US1205-30CL AT30 3.0 V 0 TO 125 US1205-33CL AT33 3.3 V 0 TO 125 US1205-36CL AT36 3.6 V
Rev. 1.4 9/25/00
2-1
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US1205
ABSOLUTE MAXIMUM RATINGSABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) ............................................................. 10V
Enable Input Voltage ........................................................... 10V
Storage Temperature Range ................................ -65°C TO 150°C
Operating Junction Temperature Range ...................... 0°C TO 150°C
PACKAGE INFORMATIONPACKAGE INFORMATION
5 PIN SOT23 ( L ) Adjustable 5 PIN SOT23 ( L ) Fixed
En
En
Gnd Vin
3 2 1
Gnd Vin
3 2 1
AT00
4 5
Adj
Vout
θJA=220°C/W
ATxx
4 5
Byp
Vout
θJA=220°C/W
ELECTRICAL SPECIFICATIONSELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over ,Cin=Co=22uF, Io=100uA, Vinmin=2.5V(Adjustable devices) Vin=Vo+1V(for fixed voltage devices), Vout=Vfb (for adjustable version only), Cbyp=470pF(for fixed output versions only), Venb=2V and Ta=25°C. Typical values refer to Ta=25 °C.Low duty cycle pulse testing are used which keeps junction and case temperatures equal to the ambient temperature.
PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS
Reference Voltage Vo -1 1 % See Table 1 for typical values (Note 4) -2 2 Line Regulation dVi Vo+1V<Vin<10 0.005 %/V Load Regulation (note 1) dVL 1mA<Io<100mA 0.8 %
100mA<Io<300mA 0.1 %
Dropout Voltage (note 2) dVio Io=100uA 10 50 mV
Io=100uA (Note 4) 13 70 mV Io=50mA 85 110 mV Io=50mA (Note 4) 100 140 mV Io=150mA 170 220 mV Io=150mA (Note 4) 204 260 mV Io=300mA 270 350 mV Io=300mA (Note 4) 324 400 mV
Ground Current (Note 3) Iq Ven=2V, Io=100uA 120 160 uA
Io=100uA (Note 4) 240 uA Io=50mA 420 600 uA Io=50mA (Note 4) 540 uA Io=150mA 2200 2900 uA Io=150mA (Note 4) 2900 uA Io=300mA 7200 9500 uA Io=300mA (Note 4) 9300 uA
Ground Current-S.D Activated Iqsd S.D pin<0.1V 0.1 uA
S.D pin=0.8V 8 Current Limit Icl Vo=0V 320 420 mA Thermal Regulation dVp Vin=10V, Io=150mA,10 mS PULSE 0.05 %/W Adjust Pin Current Iadj Vin=2.5V,Vo=Vadj 0.1 uA Enable pin input LO voltage Venl Regulator OFF 0.8 V Enable pin input HI voltage Venh Regulator ON 2 V Enable pin input LO current Venl=0V to 0.8V 0.01 uA Enable pin input HI current Venh=2V to Vin 20 uA
2-2
Rev. 1.4
9/25/00
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US1205
Note 1 : Low duty cycle pulse testing with Kelvin con-
nections are required in order to maintain accurate data. Note 2 : Drop-out voltage is defined as the minimum differential voltage between Vin and Vout required to main­tain regulation at Vout. It is measured when the output voltage drops 1% below its nominal value.
Note 3 : Ground current is the the regulator quiescent current plus the pass transistor current. The total cur­rent from the supply is the sum of the load current plus the ground pin current. Note 4 : The specification applies for the junction tem­perature of 0 to +125°C.
Pin DescRIPTIONSPin DescRIPTIONS
PIN # PIN SYMBOL PIN DESCRIPTION
4 Adj
(Adjustable only)
4 Byp
(Fixed output only)
5 Vout
2 GND
3 En 1 Vin
A resistor divider from this pin to the Vout pin and ground sets the output voltage. A 470 to 1000pF bypass capacitor connected to this pin re­duces the output noise. The output of the regulator .A minimum of 2.2uF with max ESR of 1 ohm capacitor must be connected from this pin to ground to insure stability. Ground pin. This pin must be connected to the lowest poten­tial in the system & all other pins must be at higher potential with respect to this pin. Enable pin. A low signal or left open on this pin shuts down the output.This pin must be tied HI or to Vin for normal operation. The input pin of the regulator. Typically a large storage capacitor is connected from this pin to ground to insure that the input voltage does not sag below the minimumdrop out voltage dur­ing the load transient response. This pin must always be higher than Vout by at least the amount of the dropout voltage and some margin in order for the device to regulate properly.
5 LEAD Output SOT 23 Voltage
US1205 1.242V US1205-25 2.5 V US1205-30 3.0 V US1205-33 3.3 V US1205-36 3.6 V
Table 1- Nominal output voltage v.s. part number
BLOCK DIAGRAMBLOCK DIAGRAM
Vin
Adj
Gnd
1.242V
+
THERMAL
SHUTDOWN
1205blk1-1.1
The output voltage of the adjustable device can be set using: Vo=1.242 X (1+R1/R2) Where; R1=Resistor connected from output to the Adj pin R2=Resistor connected from Adj pin to GND
Vout
En
Vin
Byp
Gnd
1.242V
THERMAL
+
SHUTDOWN
1205blk2-1.0
Vout
En
Figure 1- US1205 Adjustable block diagram
Rev. 1.4 9/25/00
Figure 2- US1205 Fixed output block diagram
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