LTC4069EDC-4.4#TRM Linear Technology, LTC4069EDC-4.4#TRM Datasheet - Page 6

• Manufacturer Part Number: LTC4069EDC-4.4#TRM
• Description: BATT CHARGER, LI ON, 750MA, 6DFN
• Manufacturer: Linear Technology

Specifications of LTC4069EDC-4.4#TRM

• Battery Type: Li-Ion
• Input Voltage: 5.5V
• Battery Charge Voltage: 4.4V
• Charge Current Max: 750mA
• Battery Ic Case Style: DFN
• No. Of Pins: 6
• No. Of Series Cells: 1
• Operating Temperature Range: -40°C To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIN FUNCTIONS
LTC4069
GND (Pin 1): Ground.
CHRG (Pin 2): Open-Drain Charge Status Output. The
charge status indicator pin has three states: pull-down,
pulse at 2Hz and high impedance state. This output can
be used as a logic interface or as an LED driver. When the
battery is being charged, the CHRG pin is pulled low by
an internal N-channel MOSFET. When the charge current
drops to 10% of the full-scale current, the CHRG pin is
forced to a high impedance state. If the battery voltage
remains below 2.9V for one quarter of the charge time, the
battery is considered defective and the CHRG pin pulses
at a frequency of 2Hz (75% duty cycle). When the NTC
pin voltage rises above 0.76 • V
• V
duty cycle).
BAT (Pin 3): Charge Current Output. Provides charge
current to the battery and regulates the fi nal fl oat voltage
to 4.2V. An internal precision resistor divider on this pin
sets the fl oat voltage and is disconnected in shutdown
mode.
VCC (Pin 4): Positive Input Supply Voltage. This pin
provides power to the charger. V
3.75V to 5.5V. This pin should be bypassed with at least
a 1μF capacitor. When V
voltage, the LTC4069 enters shutdown mode, dropping
I
6
BAT
CC
to about 1μA.
, the CHRG pin pulses at a frequency of 2Hz (25%
CC
is within 32mV of the BAT pin
CC
or drops below 0.35
CC
can range from
NTC (Pin 5): Input to the NTC (Negative Temperature
Coeffi cient) Thermistor Temperature Monitoring Circuit.
Under normal operation, connect a thermistor from the
NTC pin to ground and a resistor of equal value from the
NTC pin to V
0.35 • V
at cold, charging is suspended, the internal timer is frozen
and the CHRG pin output will start to pulse at 2Hz. Pulling
this pin below 0.016 • V
is approximately 3°C of temperature hysteresis associated
with each of the input comparator’s thresholds.
PROG (Pin 6): Charge Current Program and Charge
Current Monitor Pin. Connecting a 1% resistor, R
to ground programs the charge current. When charging
in constant-current mode, this pin servos to 1V. In all
modes, the voltage on this pin can be used to measure
the charge current using the following formula:
Floating the PROG pin puts the charger in shutdown mode.
In shutdown mode, the LTC4069 has less than 20μA supply
current and about 1μA battery drain current.
Exposed Pad (Pin 7): Ground. The Exposed Pad must
be soldered to the PCB ground to provide both electrical
contact and rated thermal performance.
I
BAT
=
CC
R
V
at hot temperatures or rises above 0.76 • V
PROG
PROG
CC
. When the voltage at this pin drops below
• 1000
CC
disables the NTC feature. There
PROG
4069fb
CC
,