L5983 STMicroelectronics, L5983 Datasheet - Page 37

• Manufacturer Part Number: L5983
• Description: IC REG SW STEP DOWN 1.5A 8VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5983

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 18 V
• Current - Output: 1.5A
• 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: 1.5 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: 497-6386 - BOARD EVAL FOR L5983
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L5983
As in the positive one, in the inverting buck-boost the current flowing through the power
MOSFET is transferred to the load only during the OFF time. So according to the maximum
DC switch current (1.5 A), the maximum output current can be calculated from
where the duty cycle is given by
Figure 35. Inverting buck-boost regulator
The GND pin of the device is connected to the output voltage so, given the output voltage,
the input voltage range is limited by the maximum voltage the device can withstand across
V
to 13 V.
As in the positive buck-boost, the maximum output current according to application
conditions is shown in
the duty cycles given by
power MOSFET are taken into account:
Equation 37
CC
and GND (18 V). Therefore, if the output is -5 V, the input voltage can range from 2.9 V
Figure
Equation
36. The dashed line considers a more accurate estimation of
Doc ID 13005 Rev 7
D
Equation
37, where power losses across diodes and the internal
=
---------------------------------------------------------------- -
–
V
IN
–
36.
V
V
OUT
SW
+
–
V
V
OUT
D
–
V
D
Application ideas
Equation
37/43
32,