1. Product profile
1.1 General description
The LD6938 series consists of small-size dual Low DropOut regulators (LDO). Each
device delivers two times 300 mA with a typical voltage drop of 240 mV at full output load.
The devices offer two separate fixed nominal output voltages (V
O(nom)
) in the range of
1.2 V to 3.3 V.
The LDO has an integrated Soft start to control the inrush current during start-up. The
output mode, when disabled, can be high-ohmic 3-state or auto discharge. Optionally a
delayed start-up circuit is available for the second output. The devices are available in a
6-bump Wafer-Level Chip-Scale Package (WLCSP) with a height of 0.47 mm.
1.2 Features and benefits
High Power Supply Rejection Ratio (PSRR)
Low output noise
Low quiescent current
Extremely low standby current ( 0.1 A)
Soft start circuit to limit inrush current
Output current limiter with foldback circuit
Overtemperature protection
Delayed output circuit for second LDO (optional)
Auto discharge or high-ohmic mode for output when disabled
WLCSP6 with 0.4 mm pitch and package size of 1.2 mm 0.8 mm 0.47 mm
1.3 Applications
1.4 Quick reference data
LD6938 series
Dual low-dropout regulators, low noise, 300 mA
Rev. 1 — 11 July 2013 Objective data sheet
Smartphones Tablet PCs
Mobile handsets Mobile internet devices
Digital still cameras Portable media players
I
O
= 300 mA for each LDO V
I
= 1.7 V to 5.5 V
PSRR = 80 dB at 1 kHz V
O
= 1.2 V to 3.3 V (fixed value)
RMS noise V
n(o)RMS
=70V
at 10 Hz to 100 kHz
Drop voltage V
do
=240mV
at I
O
= 300 mA
t
startup(reg)
200 s Quiescent current I
q
=30A for each
LDO at I
O
=0mA
