XRP7740ILB-F Exar Corporation, XRP7740ILB-F Datasheet - Page 29

• Manufacturer Part Number: XRP7740ILB-F
• Description: IC CTRLR PWM/LDO STP-DWN 40TQFN
• Manufacturer: Exar Corporation
• Type: Step-Down (Buck)r

Specifications of XRP7740ILB-F

• Number Of Outputs: 5
• Package / Case: 40-WFQFN Exposed Pad
• Topology: Step-Down (Buck) (4), Linear (1)
• Function: Standby Power and GPIOs
• Frequency - Switching: 1.5MHz
• Voltage/current - Output 1: 0.9 V ~ 5.1 V, 5A
• Voltage/current - Output 2: 0.9 V ~ 5.1 V, 15A
• Voltage/current - Output 3: 0.9 V ~ 5.1 V, 5A
• W/led Driver: No
• W/supervisor: Yes
• W/sequencer: No
• Voltage - Supply: 6.5 V ~ 20 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Current - Output: 5A, 15A
• Voltage - Output: 0.9 ~ 5.1 V
• Voltage - Input: 6.5 ~ 20 V
• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Switching Frequency: 300 KHz to 1500 KHz
• Operating Supply Voltage: 6.5 V to 20 V
• Supply Current: 50 mA
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Output Voltage: 0.9 V to 5.1 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 1016-1352 - EVAL BOARD FOR XRP77401016-1344 - IN-SOCKET PROG BRD VIA USB/GUI
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 1016-1353

REV 1.1.0
In general, the total input voltage ripple should be kept below 1.5% of VIN. The input voltage ripple also has two
major components: the voltage drop on the main capacitor
contribution to Input voltage ripple by each term can be calculated from:
Total input voltage ripple is the sum of the above:
Power MOSFETs Selection
Selecting MOSFETs with lower Rdson reduces conduction losses at the expense of increased switching losses. A
simplified expression for conduction losses is given by:
MOSFET’s junction temperature can be estimated from:
This assumes that the switching loss is the same as the conduction loss.
resistance from junction to ambient.
EXAR CONFIDENTIAL, PRELIMINARY & PROPRIETARY. DO NOT DISTRIBUTE OR COPY.
EXAR RESERVES THE RIGHT TO MAKE CHANGES TO THIS DATASHEET.
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