L5981 STMicroelectronics, L5981 Datasheet - Page 13

• Manufacturer Part Number: L5981
• Description: IC REG SW STEP DOWN 1A 8-VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5981

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 18 V
• Current - Output: 1A
• Frequency - Switching: 250kHz ~ 1MHz
• Voltage - Input: 2.9 ~ 18 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-VFQFN, 8-VFQFPN
• Power - Output: 1.5W
• Output Voltage: 3 V
• Output Current: 1 A
• Input Voltage: 2.9 V to 18 V
• Switching Frequency: 220 KHz to 275 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Low Dropout Operation: 100 % duty cycle
• For Use With: 497-6385 - BOARD EVAL FOR L5981
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L5981
4.5
4.6
Figure 8.
Inhibit function
The inhibit feature allows to put in stand-by mode the device.With INH pin higher than 1.9 V
the device is disabled and the power consumption is reduced to less than 30 μA. With INH
pin lower than 0.6 V, the device is enabled. If the INH pin is left floating, an internal pull up
ensures that the voltage at the pin reaches the inhibit threshold and the device is disabled.
The pin is also VCC compatible.
Hysteretic thermal shutdown
The thermal shutdown block generates a signal that turns off the power stage if the junction
temperature goes above 150 °C. Once the junction temperature goes back to about 130 °C,
the device restarts in normal operation. The sensing element is very close to the PDMOS
area, so ensuring an accurate and fast temperature detection.
Overcurrent protection strategy
Doc ID 13004 Rev 6
Functional description
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