US1206/1207/1208/1209
US1207,1208
Ground Current-S.D Activated
Enable pin input LO voltage
Enable pin input HI voltage
Enable pin input LO current
Enable pin input HI current
US1207,1209
Flag Output Threshold Voltage
Flag Output Hysterises Voltage
Flag Output Saturation Voltage
SYM
Iqsd
Venl
Venh
TEST CONDITION
Enable=0V
Regulator OFF (Note 4)
Regulator ON (Note 4)
Venl=0V to 0.8V (Note 4)
Venh=2V to Vin (Note 4)
MIN
TYP MAX
0.01
1
0.8
0.1
100
2
600
UNITS
uA
V
V
uA
uA
2
3.8
%Vo
Output Ramping Up
0.8
%Vo
Io=5mA
400
mV
Io=500uA
230
mV
Note 1 :
Low duty cycle pulse testing with Kelvin con-
Note 3
: Ground current is the the regulator quiescent
nections are required in order to maintain accurate data. current plus the pass transistor current. The total cur-
Note 2 :
Drop-out voltage is defined as the minimum rent from the supply is the sum of the load current plus
differential voltage between Vin and Vout required to main- the ground pin current.
tain regulation at Vout. It is measured when the output
Note 4
: The specification applies for the junction tem-
voltage drops 1% below its nominal value.
perature of 0 to +125°C.
Vthfg
Vhys
Vfsat
Pin DescRIPTIONS
PIN SYMBOL
Adj
US1208,1209
Flag
US1208
Vout
All devices
GND
All devices
Enable
US1207,1209
Vin
All devices
PIN DESCRIPTION
A resistor divider from this pin to the Vout pin and ground sets
the output voltage.
An open collector output that switches low when the output
voltage drops about 4% below its expected regulated voltage.
The output of the regulator .A minimum of 2.2uF capacitor
must be connected from this pin to ground.
Ground pin. This pin must be connected to the lowest poten-
tial 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 al-
ways be 0.6V higher than Vout in order for thedevice to regu-
late properly.
Output
Voltage
1.8V
2.5V
3.3V
1.8V
2.5V
3.3V
1.24V
1.24V
Part Number
US1206-18
US1206-25
US1206-33
US1207-18
US1207-25
US1207-33
US1208
US1209
APPLICATION INFORMATION
Stability
The US120X series of regulators require the use of an
output capacitor as part of the frequency compensation
in order to make the regulator stable. A minimum of
2.2uF capacitance and the ESR in the range of 0.5 to 2
ohm insures the stability of the system.
Table 1- Output voltage v.s. part number
Rev. 1.1
6/26/00
2-3
UNISEM [ UNISEM ]
