LTC3577EUFF#PBF Linear Technology, LTC3577EUFF#PBF Datasheet - Page 18

• Manufacturer Part Number: LTC3577EUFF#PBF
• Description: IC PWR MANAGEMENT HANDHELD 44QFN
• Manufacturer: Linear Technology

Specifications of LTC3577EUFF#PBF

• Applications: Handheld/Mobile Devices
• Voltage - Supply: 4.35 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 44-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -

LTC3577/LTC3577-1
PIN FUNCTIONS
V
connected to the USB port of a computer or a DC output
wall adapter. V
ance multilayer ceramic capacitor.
ACPR (Pin 41): Wall Adapter Present Output (Active Low).
A low on this pin indicates that the wall adapter input com-
parator has had its input pulled above its input threshold
(typically 4.3V). This pin can be used to drive the gate of
an external P-channel MOSFET to provide power to V
from a power source other than a USB port.
V
This pin can be used to drive the V
external high voltage buck switching regulator. The V
is designed to work with the LT
Consult factory for additional approved high voltage buck
regulators. See the “External HV Buck Control through the
VC Pin” section for operating information.
18
BUS
C
(Pin 42): High Voltage Buck Regulator Control Pin.
(Pin 40): USB Input Voltage. V
BUS
should be bypassed with a low imped-
®
3480, LT3653 and LT3505.
C
pin of an approved
BUS
will usually be
C
OUT
pin
CLPROG (Pin 43): Input Current Program and Input
Current Monitor Pin. A resistor from CLPROG to ground
determines the upper limit of the current drawn from the
V
of the input current, h
pin. The input PowerPath delivers current until the
CLPROG pin reaches 2V (10x mode), 1V (5x mode) or 0.2V
(1x mode). Therefore, the current drawn from V
be limited to an amount given by h
In USB applications the resistor R
to no less than 2.1k.
CHRG (Pin 44): Open-Drain Charge Status Output. The
CHRG pin indicates the status of the battery charger. If
CHRG is high then the charger is near the fl oat voltage
(charge current less than 1/10th programmed charge cur-
rent) or charging is complete and charger is disabled. A low
on CHRG indicates that the charger is enabled. For more
information see the “Charge Status Indication” section.
Ground (Exposed Pad Pin 45): The exposed package pad is
ground and must be soldered to PCB ground for electrical
contact and rated thermal performance.
BUS
pin (i.e., the input current limit). A precise fraction
CLPROG
, is sent to the CLPROG
CLPROG
CLPROG
and R
should be set
CLPROG
BUS
3577fa
will
.