MAX4978

The MAX4978-MAX4981 are available in a small 8-pin TDFN (2mm x 3mm)package and are specified over the extended -40°C to +85°C temperature range. The overcurrent limiter is available in two different thresholds: 0.9A (MAX4978/MAX4979/ MAX4980)and 1.95A (MAX4981). Once current reaches the threshold, it is held for a 20ms blanking time. If the current is still at the limit after the blanking time, the FET is turned off, and the device restarts the cycle after 160ms. The MAX4978MAX4981 overvoltage-protection devices protect low-voltage systems against voltage faults up to +28V and feature a low 85m RON FET, an active current limiter, and lithium-ion battery overcharge protection (MAX4980/MAX4981). There is an undervoltage protector with two different trip thresholds: 4.4V (MAX4978)and 2.63V (MAX4979/ MAX4980/MAX4981). The overcurrent limiter and battery voltage monitor features provide a second layer of protection for a lithiumion battery charger. The battery voltage monitor measures the voltage of a lithiumion battery and disables the FET if the battery voltage reaches 4.4V (MAX4980/MAX4981). These devices are used to protect the charger input port on a portable device. The overvoltage protector feature protects against voltages up to 28V with two different trip thresholds: 5.7V (MAX4978/MAX4980/MAX4981)and 6.8V (MAX4979).

The features of MAX4987AE can be summarized as (1)input voltage protection up to +28V; (2)integrated nFETSwitch, 85m (typ); (3)preset overvoltage protection trip level 5.7V (typ)(MAX4978/MAX4980/MAX4981)6.8V (typ)(MAX4979); (4)low-current undervoltage lockout mode; (5)overcurrent protection; (6)internal 160ms (typ)startup delay; (7)thermal-shutdown protection; (8)battery overcharge protection (MAX4980/MAX4981); (9)startup debounce time indicator (MAX4978/MAX4979); (10)small, 8-Pin (2mm x 3mm)TDFN package.

The absolute maximum ratings of MAX4978 are (1)IN, SDT: -0.3V to +30V; (2)OUT: -0.3V to IN; (3)EN, BAT: -0.3V to +6V; (4)SDT continuous current: ±50mA; (5)continuous power dissipation (TA = +70°C)8-Pin 2mm x 3mm TDFN (derate 16.7mW/°C above +70°C): 1333mW; (6)junction-to-case thermal resistance (JC)8-Pin 2mm x 3mm TDFN: 10.8°C/W; (7)Junction-to-Ambient Thermal Resistance (JA)8-Pin 2mm x 3mm TDFN: 60°C/W; (8)operating temperature range: -40°C to +85°C; (9)junction temperature: +150°C; (10)storage temperature range: -65°C to +150°C; (11)lead temperature (soldering, 10s): +300°C.