ALLEGRO APM80950 Evaluation Board User Manual

: June 5, 2024
: ALLEGRO

Table of Contents

ALLEGRO APM80950 Evaluation Board
GENERAL SPECIFICATIONS
OPERATING INSTRUCTIONS
EMI PERFORMANCE
DEMO PCB LAYOUT
Documents / Resources
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)

ALLEGRO APM80950 Evaluation Board

ALLEGRO APM80950 Evaluation
Board

EMC filter configuration

Schematic for APM80950

GENERAL SPECIFICATIONS

Specification| Min| Nom.| Max.| Units
Absolute Maximum Input Voltage| –0.3| −| 40| V
Operating Input Voltage Range| 4.5| −| 36| V
VVIN START Threshold, VVIN rising| −| −| 4.3| V
VVIN UVLO Hysteresis| 100| −| 300| mV
LED Regulation Current| −| −| 1.5| A
Enable Input| –0.3| −| VVIN + 0.3| V
VCC, ADIM, RNG, FDSET, FFn, PWM

Terminal Voltages

| –0.3| −| 7| V

BILL OF MATERIALS

Designator| Description| Footprint| Quantity| Manufacturer| Manufacturer P/N| Source| Purchase P/N
---|---|---|---|---|---|---|---
PCB| TED-0003126-PCB (APM80900/04/50/51 PCB)| N/A| 1| Allegro MicroSystems| | |
U1| APM80950 IC| QFN-32| 1| Allegro MicroSystems| APM80950KNBATR| |
RS1| Resistor, 0.2 Ω, 1/2 W, 1%| 1206| 1| Susumu| RL1632R-R200-F| Digikey| RL16R.20FCT-ND
Rfdt| Resistor, 100 kΩ, 1/16 W, 1%| 0402| 1| Panasonic Electronic| ERA- 2AED104X| Digikey| P100KDECT-ND
Rfdb| Resistor, 300 kΩ, 1/16 W, 1%| 0402| 1| Panasonic Electronic| ERJ- 2RKF3003X| Digikey| P300KLCT-ND
REN, Rffn| Resistor, 10 kΩ, 1/16 W, 1%| 0402| 2| Panasonic Electronic| ERA- 2AED103X| Digikey| P10KDECT-ND
Rdrb, RngH,

RFPWM

| Resistor, 0 kΩ, JUMPER 1/16 W| 0402| 3| Vishay Dale| CRCW04020000Z0ED| Digikey| 541-0.0JCT-ND
Rdrt, RngL| Empty| 0402| 0| | | |
CV| Capacitor, Ceramic,

1.0 µF, 50 V,10%, X7R

0.047 µF, 100 V, X7R 0805

| 0805| 1| Murata TDK| GCM21BR72A473KA37L C2012X7R2A473K125AA| Digikey| 490-4969-1-ND

445-2276-1-ND

120 Ω @ 100 MHz, 3 A

SMD

| 4.1 × 4.1 mm

3.1 mm thick

10 nF, 100 V, 10%, X7R

| 0603| 1| TDK| C1608X7R2A103K080AA| Digikey| 445-1304-1-ND
CF2| Capacitor, Ceramic,

0.47 µF, 100 V, X7R

| 1210| 1| TDK| CGA6M3X8R2A474K200AB| Digikey| 445-13052-1-ND
Cinf| Capacitor, Ceramic,

4.7 µF, 100 V, X7R

| 1210| 1| TDK| CGA6M3X7S2A475K200AB| Digikey| 445-7005-1-ND
VIN, LED+| Test Points, Red, 0.063″ diameter| 0.063″| 2| Keystone| 5010| Digikey| 5010K-ND
EN, PWM,

ADIM, FFn, VCC

| Test Points, White,

0.063″ diameter

5.08 MM PCB

CONFIGURATIONS (Refer to Datasheet)

The customer APM80950 EVB is configured for external PWM dimming operation mode only, so an external PWM dimming signal at test point PWM must be applied because the PWM pin is pulled down to GND through an internal resistor. Put jumper on P1 connector to connect EN to VIN through a resistor to enable the unit. RngH or RngL resistors determine the LED current range high or low:

RNG = VCC by making RngH = 0 Ω and RngL = Open| Full rated voltage VCSREG across current sensing resistor Rs1 = 200 mV| iLED = 0.2 / Rs1
---|---|---
RNG = GND by making RngH = Open and RngL = 0 Ω| Full rated voltage VCSREG across current sensing resistor Rs1 = 100 mV| iLED = 0.1 / Rs1

The regulation LED current level is determined by the current sensing resistor on board: iLED = 0.2 / Rsense (A) On EVB, there is one current sensing resistor, Rs1 = 0.2 Ω. Because RNG = VCC, the full LED current is 1 A.
Apply external analog dimming signal at test point ADIM. Do not leave ADIM floating. ADIM pin voltage controls the LED current reference voltage across Rs1 according to the equation below VCSREG = (VADIM – 0.4) / 5 (V) The calculation and actual test results are shown below as reference to select the desired ADIM voltage.

OPERATING INSTRUCTIONS

Refer to figure below for demo board setup. In order to enable the EVB, use the attached jumper to short the connector P1 so that EN is connected to VIN, or apply a voltage level above 1.8 V to the test point EN if the jumper is not used. Apply the desired ADIM voltage at ADIM test point. Apply PWM signal at PWM test point. Connect LED load between LED+ to GND; apply input power supply. ALLEGRO APM80950 Evaluation Board 4