Datasheet ALT80800 (Allegro) - 5

Automotive-Grade, Constant-Current 2.0 A ALT80800 PWM Dimmable Synchronous Buck LED Driver ELECTRICAL CHARACTERISTICS: Valid at VIN = 12 V, VOUT = 6 V, TJ = –40°C to 125°C, typical values at TJ = 25°C, unless otherwise noted Characteristics Symbol Test Conditions Min. Typ. Max. Unit
Input Supply Voltage VIN 4.5 – 55 V VIN Undervoltage Lockout Threshold VUVLO(ON) VIN increasing, VIN = VVCCIN, ICC = 0 mA – – 4.3 V VIN Undervoltage Lockout Hysteresis VUVLO(HYS) VIN decreasing, VIN = VVCCIN, ICC = 0 mA 100 – 300 mV VIN Pin Supply Current I VCSH – VCSL = 0.5 V, VEN = VIH_EN, IN VPWM = VIH_PWM, RON = 402 kΩ – 5 – mA VIN Pin Shutdown Current IINSD VEN = VIL_EN – 1 10 µA Output Current Sense Common Mode Voltage (measured at CSL pin) [1] VOUT VIN = 55 V, fSW = 500 kHz, iLED = 0.5 A 2.65 – 50 V Buck Switch Current Limit Threshold ISWLIM 2.5 3.25 4.0 A Buck High-Side Switch On-Resistance RDSON(HS) VBOOT = VIN + 4.3 V, TJ = 25°C, ISW = 0.5 A – 0.2 0.32 Ω Buck Low-Side Switch On-Resistance RDSON(LS) TJ = 25°C, ISW = 0.5 A – 0.15 0.24 Ω BOOT Undervoltage Lockout Threshold VBOOTUV VBOOT to VSW increasing 3.1 3.4 3.7 V BOOT Undervoltage Lockout Hysteresis VBOTUVHYS VBOOT to VSW decreasing – 750 – mV Switching Minimum Off-Time tOFFmin VCSH – VCSL = 0 V – 100 125 ns Switching Minimum On-Time tONmin – 65 90 ns Selected On-Time tON VIN = 12 V, VOUT = 6 V, RON = 42.2 kΩ 200 – 300 ns Low-Side Switching Minimum On-Time [2] tLS_ONmin – 60 90 ns tON Dithering Range fSW_DITH RON = 42.2 kΩ – ±5% – – Dithering Modulation Frequency fSW_MOD RON = 42.2 kΩ – 12.5 – kHz
REGULATION COMPARATOR AND ERROR AMPLIFIER
Load Current Sense Regulation VCSH – VCSL decreasing, SW turns on, ADIM Threshold at 100% [3] VCSREG tied to VCC 194 200 206 mV CSH Input Sense Current [4] ICSH VCSH – VCSL = 0.2 V, VOUT ≥ 5 V – –250 – µA CSL Input Sense Current ICSL VCSH – VCSL = 0.2 V, VOUT ≥ 5 V 50 75 100 µA
INTERNAL LINEAR REGULATOR
VCC Regulated Output VCC 0 mA < ICC < 14 mA, VVCCIN > 6 V 4.85 5.0 5.15 V VCC Dropout Voltage V Measure VVCCIN – VCC: VVCCIN = 4.8 V, LDO ICC = 14 mA – 0.3 0.55 V VCC Current Limit iVCCLIM VCC ≥ 4.35 V 20 – – mA V VCC Undervoltage Lockout CCUVLO Rising 3.65 3.9 4.05 V VCCUVLOHYS Hysteresis 175 225 275 mV
PWM INPUT
Logic High Voltage VIH_PWM VPWM increasing 1.8 – – V Logic Low Voltage VIL_PWM VPWM decreasing – – 1.2 V PWM Pin Pull-Up Resistance RPWMPU VCC = 5 V – 100 – kΩ
EN INPUT
Measured while PWM dimming signal applied at Maximum IC Turn Off Delay tOFFDelay EN keeping low and exceeding tOFFDelay results 10 17 – ms in shutdown Logic High Voltage VIH_EN EN increasing 1.8 – – V Logic Low Voltage VIL_EN EN decreasing – – 0.4 V Continued on the next page… 5 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com Document Outline Features and Benefits Description Applications Package Typical Application Circuit Selection Guide Specifications Absolute Maximum Ratings Thermal Characteristics Pinout Diagrams and Terminal List Tables Functional Block Diagrams Electrical Characteristics Functional Description Application Circuit Diagrams