JAJSHS0C March 2019 – March 2021 TPS92682-Q1
PRODUCTION DATA
Buck-Boost LED drivers provide the flexibility needed in applications, where the load voltage (LED string voltage) maybe less or more than the input battery voltage or the application supports multiple LED load configurations. For such applications, it is necessary to modify the design procedure presented to account for the wider range of output voltage and LED current specifications. Table 8-4 shows the design parameters for the Buck-Boost (BtB) LED driver application.
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
INPUT CHARACTERISTICS | ||||||
VIN | Input voltage range | 7 | 14 | 18 | V | |
OUTPUT CHARACTERISTICS | ||||||
VF(LED) | LED forward voltage | 2.8 | 3.2 | 3.6 | V | |
NLED | Number of LEDs in series | 3 | 6 | 9 | ||
VO | Output voltage | LED+ to LED– | 8.4 | 19.2 | 32.4 | V |
ILED | Output current | 200 | 500 | 1200 | mA | |
RRilED | LED current ripple ratio | 7.5% | ||||
rD | LED string resistance | 0.8 | 1.5 | 2.3 | Ω | |
PO(MAX) | Maximum output power | 12 | W | |||
fPWM | PWM dimming frequency | 400 | Hz | |||
SYSTEMS CHARACTERISTICS | ||||||
PO(BDRY) | Output power at CCM-DCM boundary condition | 3.5 | W | |||
ΔvIN(PP) | Input voltage ripple | 100 | mV | |||
VO(OV) | Output Overvoltage protection threshold | 40 | V | |||
VOV(HYS) | Output Overvoltage protection hysteresis | 3 | V | |||
fDM | Dither Modulation Frequency | 400 | 600 | Hz | ||
fSW | Switching frequency | 400 | kHz |