Texas Instruments Evaluation Board for the LM8850 LM8850UREV/NOPB LM8850UREV/NOPB Scheda Tecnica
Codici prodotto
LM8850UREV/NOPB
SW
PG
SDA
SCLK
VIN
VOUT
BAL
GND
EN
LM8850
3.6V
1
P
H
4.7
P
F
4.7
P
F
5V
0.05F to 1.0F
User's Guide
SNVA472A – March 2011 – Revised May 2013
AN-2119 LM8850 Evaluation Board Application Note
1
General Description
The LM8850 evaluation board is a working demonstration of a step-up DC-DC converter that has been
optimized for use with a super-capacitor. The super-capacitor protects a battery from power surges and
enables new high-power applications in mobile device architectures. The LM8850 creates an ideal rail
from 3.6V to 5.7V from an input voltage range of 2.3V to 5.5V, V
optimized for use with a super-capacitor. The super-capacitor protects a battery from power surges and
enables new high-power applications in mobile device architectures. The LM8850 creates an ideal rail
from 3.6V to 5.7V from an input voltage range of 2.3V to 5.5V, V
IN
must be 10% lower than expected V
OUT
.
An I
2
C interface controlling multiple output voltage settings, input current limits, and load currents up to 1A
provides superior user flexibility. The LM8850 operates in Auto mode, where the converter is in PFM
mode at light loads and switches to PWM mode at heavy loads or in forced PWM mode. Hysteretic PFM
extends the battery life by reducing the quiescent current to 7µA (typ.) during light load and standby
conditions. Synchronous operation provides true shutdown isolation and improves the efficiency at
medium to full load conditions.
mode at light loads and switches to PWM mode at heavy loads or in forced PWM mode. Hysteretic PFM
extends the battery life by reducing the quiescent current to 7µA (typ.) during light load and standby
conditions. Synchronous operation provides true shutdown isolation and improves the efficiency at
medium to full load conditions.
High switching frequency enables smaller passive components. Internal compensation is used for a
broader range of inductor and output capacitor values to meet system demand and achieve small system
solution size.
broader range of inductor and output capacitor values to meet system demand and achieve small system
solution size.
2
Typical Application Circuit with Super-Capacitor
Figure 1. Typical Application
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SNVA472A – March 2011 – Revised May 2013
AN-2119 LM8850 Evaluation Board Application Note
Copyright © 2011–2013, Texas Instruments Incorporated