A8672 Datasheet, PDF (3/24 Pages) Allegro MicroSystems – Fixed Frequency High Current Synchronous Buck Regulator With Fault Warnings and Power OK

A8672
Fixed Frequency High Current Synchronous Buck Regulator
With Fault Warnings and Power OK
Selection Guide
Part Number
Packing*
A8672EEGTR-T
7000 pieces per 13-inch reel
*Contact Allegro^™ for additional packing options
Absolute Maximum Ratings
Characteristic
VIN, VDD, TON, VREG, BIAS and EN
Pin Voltage
LX Pin Voltage
BOOT Pin Voltage
All Other Pins
Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
Symbol
V_I
V_LX
V_BOOT
–
T_A
T_J(max)
T_stg
Notes
With respect to GND
With respect to GND
t < 50 ns, with respect to GND
With respect to GND
E temperature range
Rating
Unit
–0.3 to 18
V
–0.6 to V_IN + 0.3
V
–2.0
V
V_LX – 0.3 to
V_LX + 8.0
V
–0.3 to 7.0
V
–40 to 85
ºC
150
ºC
–55 to 150
ºC
Table of Contents
Specifications
2
Thermal Characteristics
3
Functional Block Diagram
3
Pin-out Diagram and Terminal List
4
Electrical Characteristics
5
Functional Description
7
Basic Operation
7
Output Voltage Selection
7
Switch On-Time and Switching Frequency
7
Valley Current Limit
8
Inductor Selection
8
Output Capacitor Selection
9
Input Capacitor Selection
9
Soft-Start and Output Overloads
10
Fault Handling and Reporting
12
Control Loop
14
Control Loop Design Approach
15
Thermal Considerations
18
Regulator Efficiency
19
Layout
20
Package Outline Drawing
21
Allegro MicroSystems, LLC
2
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com