Datasheet ALT80600 (Allegro) - 7

LED Driver with Pre-Emptive Boost ALT80600 for Ultra-High Dimming Ratio and Low Output Ripple ELECTRICAL CHARACTERISTICS [1] (continued): Unless otherwise noted, specifications are valid at VIN = 16 V, TJ = 25°C, • indi- cates specifications guaranteed over the full operating temperature range with TJ = –40°C to 125°C, typical specifications are at TJ = 25°C Characteristics Symbol Test Conditions Min. Typ. Max. Unit DITHERING CONTROL
DITH Pin Source Current iDITH(src) Output current when VDITH < 0.8 V − 20 − μA DITH Pin Sink Current iDITH(sink) Output current when VDITH > 1.2 V − −20 − μA
OVERVOLTAGE PROTECTION
OVP Pin Voltage Threshold VOVP(th) OVP pin connected to VOUT ● 2.25 2.5 2.75 V OVP Pin Sense Current Threshold iOVP(th) Current into OVP pin ● 143 150 157 µA OVP Pin Leakage Current IOVPLKG VOUT = 16 V, EN = L ● − 0.1 1 µA OVP Variation at Output ΔOVP Measured at VOUT when ROVP = 249 kΩ − − 5 % Measured at V Undervoltage Detection Threshold V OUT when ROVP = 249 kΩ [2] − 3.3 4.2 V UVP(th) Measured at VOUT when ROVP = 0 Ω − 0.2 0.25 V Secondary Overvoltage Protection V Measured at SW pin; part latches when OVP2 OVP2 is detected ● 51 55 59 V
BOOST SWITCH
Switch On Resistance RSW ISW = 0.75 A, VIN = 16 V ● − 250 500 mΩ I Switch Pin Leakage Current SWLKG25 VSW = 13.5 V, PWM = VIL, TJ = 25°C − 0.1 1 µA ISWLKG85 [2] VSW = 13.5 V, PWM = VIL, TJ = 85°C − − 10 µA Switch Pin Current Limit I IC truncates present switching cycle when SW(LIM) primary limit is reached ● 3.0 3.65 4.5 A Secondary Switch Current Limit [2] ISW(LIM2) IC latches off when secondary limit is reached − 4.9 − A Minimum Switch On-Time tSW(ON) ● 45 65 85 ns Minimum Switch Off-Time tSW(OFF) ● − 50 66 ns
OSCILLATOR FREQUENCY
R Oscillator Frequency f FSET = 10 kΩ ● 1.95 2.15 2.35 MHz SW RFSET = 110 kΩ − 200 − kHz FSET Pin Voltage VFSET RFSET = 10 kΩ − 1.00 − V
SYNCHRONIZATION
V Sync Input Logic Level SYNCL FSET/SYNC pin logic Low ● − − 0.4 V VSYNCH FSET/SYNC pin logic High ● 1.5 − − V Synchronized PWM Frequency FSWSYNC ● 260 − 2300 KHz Synchronization Input Min Off-Time tPWSYNCOFF ● 150 − − ns Synchronization Input Min On-Time tPWSYNCON ● 150 − − ns Continued on the next page… Allegro MicroSystems, LLC 7 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com Document Outline Features and Benefits Description Applications Package Selection Guide Absolute Maximum Ratings Thermal Characteristics Typical Application – SEPIC Functional Block Diagram Pinout Diagram and Terminal List Electrical Characteristics Functional Description Enabling the IC Powering Up: LED Detection Phase Powering Up: Boost Output Undervoltage Soft Start Function Frequency Selection Synchronization Loss of External Sync Signal Switching Frequency Dithering Clock Out Function LED Current Setting PWM Dimming Pre-Emptive Boost (PEB) Analog Dimming with APWM Pin Extending LED Dimming Ratio Analog Dimming with External Voltage VDD Shutdown Fault Detection and Protection LED String Partial-Short Detect Boost Switch Overcurrent Protection Input Overcurrent Protection and Disconnect Switch Setting the Current Sense Resistor Input UVLO Fault Protection During Operation Fault Recovery Mechanism Package Outline Drawing Appendix A: Design Example