pt6112 China Resources Powtech (Shanghai) Co., Ltd, pt6112 Datasheet - Page 9

• Manufacturer Part Number: pt6112
• Description: Standalone Linear Li-ion Battery Charger With Thermal Regulation
• Manufacturer: China Resources Powtech (Shanghai) Co., Ltd

Undervoltage Lockout (UVLO)
An internal undervoltage lockout circuit monitors the
input voltage and keeps the charger in shutdown mode
until VCC rises above the undervoltage lockout
threshold. The UVLO circuit has a built-in hysteresis of
200mV. Furthermore, to protect against reverse current
STABILITY CONSIDERATIONS
The constant-voltage mode feedback loop is stable
without an output capacitor provided a battery is
connected to the charger output. With no battery
present, an output capacitor is recommended to reduce
ripple voltage. In constant current mode, the PROG pin
is in the feedback loop, not the battery. The
constant-current mode stability is affected by the
impedance at the PROG pin. With no additional
Adapter/USB Applications
For USB or adapter application, there is ±10% voltage
variation in the power supply; this device should be
damaged if input voltage is higher than 5.5V. To
protect the device, a 5.6V break down diode is
suggested connects between V
of applications.
EXTERNAL COMPONENT SELECTION GUIDE
With no battery present, an output capacitor is
recommended to reduce ripple voltage. When using
high value, low ESR ceramic capacitors, it is
recommended to add a 1Ω resistor in series with the
China Resources Powtech (Shanghai) Limited
PT6112_DS Rev EN_1.0
Output Capacitors
CC
and GND in this kind
WWW.CRPOWTECH.COM
Charger with Thermal Regulation
Standalone Linear Li-Ion Battery
in the power MOSFET, the UVLO circuit keeps the
charger in shutdown mode if VCC falls to within 30mV
of the battery voltage. If the UVLO comparator is
tripped, the charger will not come out of shutdown
mode until V
capacitance on the PROG pin, the charger is stable with
the programming resistor value as high as 20k.
However, additional capacitance on this node reduces
the maximum allowed program resistor. The pole
frequency at the PROG pin should be kept above
100kHz.
capacitor. No series resistor is needed if tantalum
capacitors are used.
Use a resistor with 1% precision to increase the
charging current accuracy.
Programmed resistor
CC
rises 100mV above the battery voltage.
PT6112
Page 9