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| A8504 |
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 ALLEGRO
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4 page 
WLED/RGB Backlight Driver for Medium Size LCDs A8504 4 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com ELECTRICAL CHARACTERISTICS , valid at TA = –40°C to 85°C, typical values at TA = 25°C, VIN = 5 V, unless otherwise noted Characteristics Symbol Test Conditions Min. Typ. Max. Units Input Voltage Range VIN 4.2 – 5.5 V Undervoltage Lockout Threshold VUVLO VIN falling – – 4 V UVLO Hysteresis Window VUVLOhys – 0.2 – V Supply Current ISUP Switching at no load, TA = 25°C – 5 – mA Shutdown PWM = VIL – 0.1 1 μA Error Amplifier Error Amplifier Open Loop Gain AVEA –60– dB Error Amplifier Unity Gain Bandwidth UGBEA –3– MHz Error Amplifier Transconductance GmEA ∆ICOMP = ±10 μA – 850 – μA/V Error Amplifier Output Sink Current IEAsink VLED1-8 = 1 V – 280 – μA Error Amplifier Output Source Current IEAsource VLED1-8 = 0 V – –280 – μA Boost Controller Switching Frequency fSW RFSET = 13 kΩ, SKIP = VIL 1.8 2 2.2 MHz RFSET = 26.1 kΩ, SKIP = VIL –1– MHz RFSET = 32.4 kΩ, SKIP = VIH – 200 – kHz Minimum Switch Off-Time tOFFmin –70– ns Logic Input Levels (PWM, SELx, and SKIP pins unless otherwise specified) Input Voltage Level Low VIL – – 0.4 V Input Voltage Level High VIH 1.5 – – V Input Leakage Current (PWM, and SKIP pins) IIleak VI(pin) = 5 V, TA = 25°C – – 100 μA Input Leakage Current (SELx pins) ISELleak ––1 μA Over Voltage Protection (OVP) Output Overvoltage Rising Limit VOVP 28 – 32 V OVP Sense Current IOVPH –49– μA OVP Release Current IOVPL –44– μA OVP Leakage Current IOVPleak VVOP = 21 V – 0.1 – μA Boost Switch Switch On Resistance Rds(on) ISW = 1.5 A – 225 – mΩ Switch Leakage Current ISWleak VSW = 5 V, TA = 25°C – – 1 μA VSW = 21 V – 1 – μA Switch Current Limit ISWlim 1.6 2 – A Continued on the next page… |
