ALLEGRO A80802 Evaluation Board User Guide
- June 13, 2024
- ALLEGRO
Table of Contents
APEK80802KEJ-01-BB-T
A80802 Evaluation Board User Guide
DESCRIPTION
The ALT80802 Evaluation Board is designed to help system designers evaluate the operation and performance of the ALT80802 Wide Input Voltage, Adjustable Frequency, Buck-Boost or Buck, 2 Amp LED Driver. This board is configured in a buck-boost configuration, which allows operation while driving LED strings with a forward voltage drop below, equal to or higher than the input voltage.
FEATURES
- ALT80802 Buck-Boost or Buck LED driver
- Optional external binning/dimming control of regulated LED current level
- Optional PWM control for pulse width modulation dimming of LED current
- Fault pin (FFn) output with externally supplied pull-up rail
Table 1: ALT80802 Evaluation Board Configurations
| Configuration Name | Part Number | Output Current (mA) |
|---|---|---|
| ALT80802 Buck-Boost Evaluation Board | APEK80802KEJ-01-BB-T | 350 |
Table 2 : General Specifications
| Specification | Min | Nom | Max | Units |
|---|---|---|---|---|
| Input Operating Voltage | 3.8 | – | 50 | V |
| Switching Frequency | – | 2 | – | MHz |
USING THE EVALUATION BOARD
This section provides an overview of the connections and configuration options of the ALT80802 Evaluation Board. Each group of connections highlighted in Figure 2 has a detail section below. The ALT80802 datasheet contains detailed information on the use and functionality of each pin and should be consulted for more detailed information than is contained in this user guide.
CAUTION: THE LEDS SUPPLIED ON THIS BOARD ARE VERY BRIGHT. PLEASE DO NOT LOOK DIRECTLY AT THEM. THE STATIC SHIELDING BAG THAT WAS PROVIDED WITH THIS BOARD CAN BE USED AS A SHIELD TO HELP REDUCE THE INTENSITY OF THE LIGHT.
Power Input
Connect a power supply to VIN and GND of the input terminal block or to the VIN and GND test points. It is best to use short, cables that are at least 18 AWG.
Board Configuration
LEDs: The evaluation board is equipped with 4 white LEDs. The number of LEDs
can be connected as desired by placing shunts on the pins of the “# of LEDs” 5
× 2 pin header. Alternatively, a different LED or string of LEDs can be
powered by shorting the “EXT” pair of pins on the 5 × 2 pin header and
connecting the LEDs to the LED+ and LED– test points.
The “Binning” 2-pin header allows the user to apply an external voltage signal
to adjust the regulated LED current level. Small variations above and below
200 mV applied to the BIN/DIM test points will result in a significant change
in LED current. Consult the evaluation board schematic for details on how this
network is set up.
The ALT80802’s FFn pin is an open-drain pull-down that asserts low during
certain fault conditions. The FFn test point on the evaluation board is tied
directly to the ALT80802’s FFn pin. Apply a voltage to the EXT test point to
provide an appropriate pull-up if FFn is to be monitored.
SCHEMATIC
Figure 3 below illustrates the ALT80802 evaluation board schematic.
PCB LAYOUT
Figures 4 and 5 below show the top and bottom layers of the ALT80802 evaluation board.
BILL OF MATERIALS
Table 3 : ALT80802 Evaluation Board Bill of Materials
ELECTRICAL COMPONENTS
Designator| Quantity| Description| Manufacturer|
Manufacturer Part Number
PCB| 1| ALT80802 2 MHz Buck Boost EVAL PCB, Rev. 2.1| Allegro MicroSystems| –
U1| 1| ALT80802 2 A LED Driver| Allegro MicroSystems| –
R1| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW06038K06FKEA
R2| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW060310K0FKEA
R3| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW06032K49FKEA
R4| 0| Not used| –| –
R5, R9| 2| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW06032K00FKEA
R6| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW0603120RFKEA
R7| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW06031K00FKEA
R8| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Panasonic| –
R10| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW060340R2FKEA
R11| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Vishay| CRCW0603100RFKEA
RBIN| 1| Resistor, 8.06 kΩ, 1/10 W, 1%| Panasonic| ERJ-3EKF5600V
C1| 1| Capacitor, Ceramic, 4.7 µF, 50 V, 10%, X7R| TDK|
C2, C9| 0| Not used| –| –
C7| 1| Capacitor, Ceramic, 0.47 µF, 50 V, 10%, X7R| TDK| CGA4J3X7R1H474K125AB
C3, C8, C10| 3| Capacitor, Ceramic, 100 nF, 50 V, 10%, X7R| Murata|
GCJ188R71H104KA12D
C4| 1| Capacitor, Ceramic, 220 nF, 50 V, 10%, X7R| TDK| CGA2B2X7R1C224K050BA
C5| 1| Capacitor, Ceramic, 1.5 nF, 50 V, 5%, C0G| Murata| GCM1885C1H152JA16D
C6| 1| Capacitor, Ceramic, 22 pF, 100 V, 5%, C0G| Myrata| GCM1885C2A220JA16D
C11| 1| Capacitor, Ceramic, 560 pF, 100 V, 10%, X7R| Kemet| C0603Y561K1RACAUTO
D1| 1| Diode, Schottky, 60 V, 5 A, 670 mV @ 5 A| Diodes Incorporated|
PDS560-13
D2| 1| Diode, Schottky, 40 V, 1 A, 410 mV @ 1 A| Diodes Incorporated|
1N5819HW-7-F
Q1| 1| Transistor, NPN, 65 V, 0.1 A SOT23| Onsemi| BC846ALT1G
L1| 1| Inductor, 4.7 µH, 9.8 ASAT 15.32 mΩ Max| Vishay| IHLP4040DZER4R7M8A
LED1, LED2, LED3, LED4| 4| LED White 700 mA, 3.05 V| Osram| LUW CQAR-MUNQ
JP1| 1| Header, 2 × 5, 0.1″| Molex| 15912100
JP2| 1| Header, 2 × 1, 0.1″| Sullins| PEC02SAAN
X1| 1| Connector, Screw Terminal, 2-way| On Shore Techmology| OSTTC022162
‘VIN’, ‘EN’, ‘FFn’, ‘SW’, ‘LED+’, ‘CS’| 6| Test Points, Red, 0.063″ diameter|
Keystone| 5010
‘EXT’, ‘BIN/DIM’, ‘LED-‘| 3| Test Points, White, 0.063″ diameter| Keystone|
5012
‘GND’| 3| Test Points, Black, 0.063″ diameter| Keystone| 5011
‘VSS’-BAR| 1.2″| WIRE BUS BAR 18AWG 100′| –| –
Jumper| 1| SHUNT LP W/ HANDLE 2 POS 30AU| TE Connectivity| 881545-2
OTHER COMPONENTS
Designator| Quantity| Description| Manufacturer|
Manufacturer Part Number
HS1| 1| Heatsink| CTS| 7-340-2PP-BA
HS2| 1| Heatsink| CTS| 7-340-1PP-BA
SCREW| 3| Machine Screw PAN PHILLIPS 2-56| –| PMSSS 256 0025 PH
HEX NUT| 3| HEX NUT 3/16′ STN STEEL 2-56| –| NHSS256
WASHER| 3| WASHER INT TOOTH #2 STN STEEL| –| INT LWSS 002
RELATED LINKS
https://www.allegromicro.com/en/products/regulate/led-drivers/led-drivers- for-lighting/alt80802
Revision History
| Number | Date | Description |
|---|---|---|
| – | 25-May-23 | Initial release |
Copyright 2023, Allegro MicroSystems.
Allegro MicroSystems reserves the right to make, from time to time, such
departures from the detail specifications as may be required to permit
improvements in the performance, reliability, or manufacturability of its
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information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but
not limited to life support devices or systems, in which a failure of
Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable.
However, Allegro MicroSystems assumes no responsibility for its use; nor for
any infringement of patents or other rights of third parties which may result
from its use.
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Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com