Engineered with a high-voltage tolerant process and precise voltage detection technology, the NB7400 is tailored to meet the stringent safety requirements of modern battery-powered applications.
The NB7400 offers an additional layer of security in multi-cell battery applications. While primary protection ICs typically manage standard charge/discharge cycles and basic threshold monitoring, secondary protection ICs are critical in scenarios where the primary circuitry fails or becomes unresponsive. The NB7400 detects abnormal overcharge conditions independently and triggers a fuse-blowing mechanism to interrupt the charging path permanently, effectively preventing hazardous scenarios such as thermal runaway or battery rupture.
The NB7400 supports the supply voltage tolerance of up to 32V, and offers overcharge detection voltages programmable between 4.20 and 4.85V with high accuracy (±20mV at 25°C). It also incorporates an optional overcharge timer reset delay, ensuring resilience against noise-induced false triggers, with delay times configurable to 2, 4, or 6 seconds. Key attributes of the NB7400 include an ultra-low operating current of just 2.5µA during normal operation, and switches to a minimal shutdown current of 0.2µA to conserve battery life, activated when any cell voltage falls below a configurable threshold. To support external components like real-time clocks, it integrates a built-in voltage regulator delivering a stable output between 1.5 and 3.3V, accurate within ±2%.
The NB7400 is available in multiple configurations, with selectable set voltages, delay times, and output voltages tailored to specific design needs. The product is manufactured in a compact DFN(PL)2020-8-GH package, suitable for use in small-sized applications and gadgets.
NB7400GH specifications:
High Voltage Tolerant Process
Absolute maximum ratings: 3V
Low Supply Current
Normal operation (Cell voltage: 4.15V, 4 cells): Typ. 2.5μA
Shutdown (Standby): Max. 0.2μA
High-accuracy Voltage Detection for 1 to 4 Cells
Overcharge detection voltage (VDET1n) and accuracy:
4.20 to 4.85V, ± 0.020V (Ta = 25°C), ± 0.025V (0°C < Ta < 60°C)
Overcharge detection delay time with delay time shortening: (1) 2-, 4-, or 6-sec
Overcharge release voltage (VREL1n): VDET1n−0 V to VDET1n−0.4 V
Overcharge release voltage condition: Voltage Release type
Output Voltage
VROUT (built-in voltage regulator) pin output voltage (VVROUT) and accuracy: 1.5 V to 3.3 V, ±2%
COUT pin (CMOS output, active-high) output voltage: Typ. 4.7 V
Shutdown Function
Shutdown detection voltage (VSHTDn) and accuracy: 2.0 (2) to 3.0, ± 0.05V
Shutdown detection voltage delay time: 2-, 4-, or 6-sec
Shutdown release voltage (VSHTRn): VSHTDn+0.2V
Selectable Overcharge Timer Reset Delay
Package NB7400GH: DFN(PL)2020-8-GH
Datasheet NB7400GH: Consumer version
(1) The delay time is shortened to approx. 1/80 by applying 4 ± 0.2V to the VDD ‒ VC1 pins
(2) VSHTD2 ≥ 2.3V, only when two cells connected in series
