Texas Instruments TPS76933, User Manual

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Design Strategy
1-3 Introduction
1.2 Design Strategy
The TI SLVP125 EVM provides a circuit to simultaneously compare the
performance of two LDOs in a SOT23 package. The EVM provides proven,
demonstrated reference designs and test modes to aid in choosing and
evaluating LDOs. A programmable high speed transient generator generates
either line or load transients. The transient slew rate, and the impact of the
transients on the load/line are adjustable. A 10x amplifying operational
amplifier (op amp) makes measurements of the dropout voltages easier and
more accurate. To avoid influencing each other, each LDO can be powered by
its own power supply. Jumpers allow settings of minimum/maximum load as
well as device-enable and transient impact functions. There is enough room
on the EVM to evaluate different types of output capacitors including ESR
behaviors. Many test points allow the measuring of input, output, and dropout
voltage.
The EVM is shipped with a TPS76933 that provides a 3.3-V output voltage.
The maximum output current is 100 mA. The 100 mA-output power level is a
reasonable selection criteria for powering DSPs and battery-supplied
applications such as mobile phones and laptop cards.
The TPS760xx, TPS761xx, TPS763xx, TPS764xx, TPS769xx, TPS770xx
LDO family provides several output currents and voltages combined with
options like very low noise or high accuracy.
Table 1–1 summarizes the LDO families and their features.
Table 1–1. Summary of LDO Families and Their Features
TPS760xx TPS761xx TPS763xx TPS764xx TPS769xx TPS770xx
Maximum input voltage range [V] 16 (PNP) 10 (PMOS) 13.5(PMOS)
Maximum output current [mA] 50 100 150 150 100 50
Typical quiescent current [
µ
A] 850 2600 85 17
Typical dropout voltage [mV] 120 210 300 71 35
Typical output noise [
µ
Vrms] 190 140 30 190
Accuracy over line, load, and
temperature
3% 2%
PSRR (at 1 kHz, CO = 10
µ
F,
TJ = 25
°
C)
60 dB
Package SOT23
External cap > 4.7
µ
F
Available Voltage Option [V] 3, 3.2, 3.3, 3.8, and 5
1.6, 1.8, 2.5,
2.7, 2.8, 3,
3.3, 3.8, 5,
and adj
2.5, 2.7,
2.8, 3, 3.3
1.2, 1.5, 1.8, 2.5, 2.7,
2.8, 3, 3.3, 5, and adj.
Performance Advantage Low dropout
Low quiescent current,
low noise
Low dropout, ultra low
quiescent current, high
accuracy