ncp367 ON Semiconductor, ncp367 Datasheet - Page 7

• Manufacturer Part Number: ncp367
• Description: Ncp367 Battery Charge Front-end Protection, Usb And Ac/dc Supply Compliant
• Manufacturer: ON Semiconductor

Operation
protection of the portable devices during the Li ion battery
charge.
the down stream system (charger, transceiver, system...)
against the power supply transients such as inrush current
or defective functionality. Additional protection level is
offered with the overcurrent block which eliminates
current peak or opens the charge path if an overcurrent
default appears.
the input power supply is connected, allowing to open
charge path if Li ion battery voltage exceeds 4.3 V, caused
by CCCV charger or battery pack fault.
support very high charge DC current up to 2.3 A. The
overcurrent threshold can be externally adjusted with a
pull-down resistor and gain select pin is available to divide
current limit threshold with internal fixed gain. Allowing
to adjust with logic pin the overcurrent threshold if
USB/500 mA or WA/1.5 A is detected, without changing
R
faults are signalized thanks to the open drain FLAG pin, by
pulling its down.
Undervoltage Lockout (UVLO)
device has a built−in undervoltage lock out (UVLO)
circuit. During Vin positive going slope, the output remains
disconnected from input until Vin voltage is above 1.85 V
plus hysteresis nominal. This circuit has a 80 mV
hysteresis to provide noise immunity to transient condition.
Overvoltage Lockout (OVLO)
overvoltage, the device has a built-in overvoltage lock out
(OVLO) circuit. During overvoltage condition, the output
remains disabled as long as the input voltage exceeds this
threshold.
OVLO. This circuit has a 100 mV hysteresis to provide
noise immunity to transient
FLAG Output
systems that a fault has occurred.
or internal temperature thresholds are exceeded and
remains low until between minimum driving voltage and
UVLO threshold. When Vin level recovers normal
condition, FLAG is held high. The pin is an open drain
output, thus a pull up resistor (typically 1 MW − Minimum
10 kW) must be provided to Vcc. FLAG pin is an open drain
output, which is able to support 1 mA maximum.
ILIM
The NCP367 is an integrated IC which offers a complete
First, the input pin is protected up to +30 V, protecting
More of that, the battery voltage is monitored all along
The integrated pass element (PMOS FET) is sized to
Undervoltage, Overvoltage, Overcurrent and thermal
To ensure proper operation under any conditions, the
To protect connected systems on Vout pin from
FLAG output is tied to low as long as Vin is higher than
NCP367 provides a FLAG output, which alerts external
This pin is tied to low as soon as the OVLO, OV
resistor, in example.
conditions.
APPLICATION INFORMATION
BAT
http://onsemi.com
, I
OCP
7
EN Input
to low or connected to ground. A high level on the pin,
disconnects OUT pin from IN pin. EN does not overdrive
a UVLO or OVLO fault.
Overcurrent Protection (OCP)
function, from wall adapter to battery. That means the
current across the internal PMOS is regulated and cut when
the value, set by external RSEL resistor, exceeds I
longer than t
allowing to have a maximum OCP value when I
directly connected to GND.
the OCP value is decreased.
in case of different charge rate is necessary (Wall adapter
and USB, for example).
depending on R select resistor, which is connect between
pin 4 and GND. When the GS pin is tied to 1.2 V (high logic
level) the preselected current limit is divided by 2.75.
Thanks to this option, both fast charge or USB charge are
authorized with the same device.
FLAG output is tied to low, allowing the mController to take
into account the fault event and then open the charge path.
current is limited up to I
allow capacitor charge and limit inrush current. If the I
threshold is exceeded over 1.8 ms, the device enter in OCP
burst mode until the overcurrent event disappears.
1500
1000
To enable normal operation, the EN pin shall be forced
This device integrates the overcurrent protection
An internal resistor is placed in series with the pin
By adding external resistors in series with I
An additional logic pin, GS (gain select), is very useful
By setting GS to 0.4 V, overcurrent thresholds are
Typical R
During overcurrent event, charge area is opened and
At power up (accessory is plugged on input pins), the
500
Figure 12. I
0
0
100
GS = High
LIM
REG
OCP
calculation is following:
.
200
GS = Low
R
LIM
versus R
1.5 A version
300
(kW) = 249 / I
LIM
Rilim(kW)
400
LIM
during 1.8 ms (typical), to
, GS = low and high,
500
OCP
600
− 165
LIM
700
and GND,
LIM
pin is
800
LIM
LIM