NE57600 Philipss, NE57600 Datasheet - Page 10

• Manufacturer Part Number: NE57600
• Description: One-cell Lithium-ion battery protection with over/undercharge and overcurrent protection
• Manufacturer: Philipss

Philips Semiconductors
FET STATUS FOR NORMAL AND ABNORMAL
CONDITIONS
Normal mode:
Overcharge mode:
Overdischarge mode:
Overcurrent mode:
PACKING METHOD
2001 Oct 03
Normal (charging or discharging)
Overcharge (charging)
Overcharge (discharging)
Overdischarge (discharging)
Overdischarge (charging)
Overcurrent (charging or discharging)
One-cell Lithium-ion battery protection with
over/undercharge and overcurrent protection
GUARD
BARCODE
BAND
LABEL
Operating Mode and
Charging Condition
BOX
Overdischarge detection voltage < battery
voltage <overcharge detection voltage
Discharge current < overcurrent detection
level
Battery voltage > overcharge detection
voltage
Overdischarge detection voltage > battery
voltage
Discharge current > overcurrent detection
level
voltage between VM and GND =
discharge current
(discharge or charge FET)
TAPE
FET (CF)
Charge
FET ON resistance
OFF
OFF
OFF
ON
ON
ON
Figure 11. Tape and reel packing method.
Discharge
FET (DF)
OFF
OFF
ON
ON
ON
ON
REEL
ASSEMBLY
10
pack. The total resistance of the battery pack is given by Equation 1.
the MOSFET. During a short-circuit, the discharge current can easily
Selecting the Optimum MOSFETs
For a single-cell battery pack, a logic-level MOSFET should be
used. These MOSFETs have turn-on thresholds of 0.9 V and are
considered full-on at 4.5 V VGS. Some problem may be
encountered in not having enough gate voltage to fully turn-ON the
series MOSFETs over the battery pack entire operating voltage. If
one deliberately selects an N-Channel MOSFET with a much
greater current rating, a lower RDS
attained.
The MOSFETs should have a voltage rating greater than 20 V and
should have a high avalanche rating to survive any spikes
generated across the battery pack terminals.
The current rating of the MOSFETs should be greater than four
times the maximum “C-rating” of the cells. The current rating,
though, is more defined by the total series resistance of the battery
The total pack resistance is typically determined by the system
requirements. The total pack resistance directly determines how
much voltage droop will occur during pulses in load current.
Another consideration is the forward-biased safe operating area of
reach 10–15 times the “C-rating” of the cells. The MOSFET must
survive this current prior to the discharge MOSFET can be turned
OFF. So having an FBSOA envelope that exceeds 20 amperes for
5 ms would be safe.
R
bat(tot)
= RDS
(on)
+ R
cell
TAPE DETAIL
(on)
over the entire range can be
(Equation 1)
COVER TAPE
NE57600
CARRIER TAPE
Product data
SL01305