1/14March 2005
■INPUT VOLTAGE FROM 2.5V T O 6V
■STABLE WITH LOW ESR CERA M IC
CAPACITORS
■U LTRA LOW DROPOUT VOLTAG E (100mV
TY P. AT 150mA LOA D, 0.4m V TYP. AT 1mA
LOAD)
■VERY LOW QUIESCENT CURRENT (85µ A
TY P. AT NO LO AD, 170µ A TYP. AT 150m A
LOAD; MA X 1.5 µA IN OFF MO D E)
■GUARANTEED OUTPUT CURRENT UP TO
150mA
■WIDE RANGE OF OUTPUT VOLTAGE: 1.2V;
1.22 V; 1. 25V; 1.35V; 1.5V; 1.8V; 2V; 2.1V;
2.2V; 2.4V; 2.5V; 2.6V; 2.7V; 2.8V; 2.85V;
2.9V; 3V; 3.1V; 3.2V; 3.3V; 4.7V; 5V
■FAST TURN-O N TIME: TYP. 200µs [CO=1µF,
CBYP= 10nF AND IO=1mA]
■LOGIC-CONTROLLED ELECTRONIC
SHUTDOWN
■INTERNAL CURRENT AND THERMAL LIMIT
■OUTPUT LOW NOISE VOLTAGE 30µ VRMS
OV ER 10Hz to 100KHz
■S.V.R. OF 60dB AT 1KHz, 50dB AT 10KHz
■TEMPERATURE RANGE: -40°C TO 125°C
DESCRIPTION
The LD3 985 provides up to 150mA, from 2.5V to
6V inpu t voltage.
The ultra low drop-voltage, low quiescent current
and low noise make it suitable for low power
applications and in battery powered systems.
Regulator ground current increases only slightly in
dropout , further prolonging th e batt ery life. Power
supply rejection is better than 60 dB at low
frequencies and starts to roll off at 10KHz. High
power s upply rejection is maintained do wn to l ow
input voltage levels common to battery operated
circuits. Shutdown Logic Control function is
avai lable, this m eans t hat when the device is used
as local regulator, it is possibl e to put a part of the
board in standby, decreasing the total power
consumption. The LD3985 is designed to work
with low ESR ceramic capacitors. Typical
applications are in mobile phone and similar
battery po wered wireless systems.
LD3985
SERIES
ULTRA LOW DROP-LOW NOISE BICMOS VOLTAGE
REGULATORS LOW ESR CAPAC IT ORS COMPATIBLE
Fi gure 1 : Schematic Diagr am
Flip-Chip
(1.57x1.22) TSOT23-5LSOT23-5L
Rev. 9