1FEATURES
• 2-, 3-, or 4-Cell Secondary Protection
• Low Power Consumption I CC < 2 μA
[VCELL(ALL) < V(PROTECT)]
• Fixed High Accuracy Overvoltage Protection
Threshold
– bq29410 = 4.35 V
– bq29411 = 4.40 V
– bq29412 = 4.45 V
– bq29413 = 4.50 V
– bq29414 = 4.55 V
– bq29415 = 4.60 V
– bq29419 = 4.30 V
• Programmable Delay Time of Detection
• High Power Supply Ripple Rejection
• Stable During Pulse Charge Operation

APPLICATIONS
• 2nd-Level Overvoltage Protection in Li-Ion
Battery Packs in:
– Notebook Computers
– Portable Instrumentation
– Portable Equipment

DESCRIPTION
The bq2941x is a secondary overvoltage protection
IC for 2-, 3-, or 4-cell lithium-ion battery packs that
incorporates a high-accuracy precision overvoltage
detection circuit. It includes a programmable delay
circuit for overvoltage detection time.

FUNCTION
Each cell in a multiple-cell pack is compared to an
internal reference voltage. If one cell reaches an overvoltage condition, the protection sequence
begins. The bq2941x device starts charging an
external capacitor through the CD pin. When the CD
pin voltage reaches 1.2 V, the OUT pin changes from a low level to a high level.