STEVAL-ILL0V Digital constant-current controller for LED driving based on the STM8S08x Data brief Features DC input voltage: 8 V Buck stage adapts output voltage to drive LEDs with selected current Four DC-DC buck converters allow driving of LED strings, managing up to 0 W Employs W LEDs to obtain 0 W-per-string (0 LEDs in series in each string) Low voltage-sensing circuitry Logic level MOSFETs driven by the microcontroller without gate driver (ground referred) High efficiency (up to 98%) RoHS compliant Description The purpose of the STEVAL-ILL0V demonstration board is to present a new digital approach to performing real average current control on an LED streetlighting platform. This LED streetlight platform is developed on a DC-DC inverse buck converter, taking advantage of power switch control and conditioning signal circuitry for current sensing. Benefits of this design include low energy consumption, low maintenance, and reduced size and weight. The solution is customized for streetlighting applications, but can be extended to many other segments. STEVAL-ILL0V November 00 Doc ID 77 Rev /6 For further information contact your local STMicroelectronics sales office. www.st.com 6
Schematic diagrams STEVAL-ILL0V Schematic diagrams Figure. Control stage schematic ( of ) C8 00nF C 0pF MHz C6 0pF J SPI_MOSI_LCD R X PA UART_RX PA5 UART_TX JOY_LEFT JOY_RIGHT JOY_UP JOY_DOWN PWM-FirstString PWM-SecondString PWM-ThirdString PWM-FourthString 0 M R J9 Comm Connector J0 CONA R5 68R TIM_CH RESET# PD/TIM_CH/[TIM_CH] Swim Connector L5 BEAD C5 80pF R8 R6 0 R7 0 PD_Swim _VDDA C0 0uF C 00nF RESET# OSC IN OSC OUT TIM_CH PWM-PC PWM-PC PWM-PC PWM-PC PC6_MOSI VDDA 70nF C 0nF C7 R 0K 8 57 58 59 60 6 6 6 6 7 6 6 0 9 8 0 5 5 6 7 8 0 7 9 5 0 9 9 Enable_ Enable_ k7 PB_JOYSTICK_LEFT PB5_JOYSTICK_RIGHT PB6_JOYSTICK_UP PB7_JOYSTICK_DOWN U SW reset NRST PA/OSCIN PA/OSCOUT PA/TIM_CH/[TIM_CH] PA/UART_RX PA5/UART_TX PA6/UART_CK VCAP PB0/AIN0/[TIM_CHN] PB/AIN/[TIM_CHN] PB/AIN/[TIM_CHN] PB/AIN/[TIM_ETR] PB/AIN/[I C_SCL] PB5/AIN5/[I C_SDA] PB6/AIN6 PB7/AIN7 PC/TIM_CH PC/TIM_CH PC/TIM_CH PC/TIM_CH PC5/SPI_SCK PC6/SPI_MOSI PC7/SPI_MISO PD0/TIM_CH/[TIM_BKIN]/[ CLK_CCO] PD/SWIM PD/TIM_CH/[ADC_ETR] PD/TIM_CH/[BEEP] PD5/UART_TX PD6/UART_RX PD7/TLI/[TIM_CH] VDDIO_ VDDIO_ VDD VDDA VSS VSSA VSSIO_ VSSIO_ STM8S08RB PE0/CLK_CCO PE(T)/IC_SCL PE(T)/IC_SDA PE/TIM_BKIN PE PE5/SPI_NSS PE6/AIN9 PE7/AIN8 PF0/AIN0 PF/AIN PF/AIN PF5/AIN PF6/AIN PF7/AIN5 PG0/CAN_TX PG/CAN_RX 5 PG 6 PG 7 PG 9 PG5 50 PG6 5 PG7 Vref + Vref - PI0 8 7 6 5 8 56 55 5 5 5 PE6-Ch9-SecondString PE7-Ch8-FirstString PF0-Ch0-ThirdString PF-Ch-FourthString PF-Ch-Dimming k7 R0 k7 R k7 R Vref + R0 0R Enable FirstString Enable SecondString Enable ThirdString Enable FourthString _VDDA Sensing-SecondString Sensing-First String Sensing-ThirdString Sensing-FourthString Dimming Rk R5k R7k R6k R9 0R C9 uf LCD_CS PG PG PG D5 D6 D7 D8 R8 k P 0k GND JOY_SEL PD7_JOYSTICK_SEL PG0_LCD_CS R9 0R /6 Doc ID 77 Rev
STEVAL-ILL0V Schematic diagrams Figure. Control stage schematic ( of ) Doc ID 77 Rev /6
Schematic diagrams STEVAL-ILL0V Figure. Power stage schematic /6 Doc ID 77 Rev
STEVAL-ILL0V Revision history Revision history Table. Document revision history Date Revision Changes -Apr-00 Initial release. -Nov-00 Changed board photo on coverpage Divided control stage schematic diagram into two figures (Figure and Figure ) to improve readability Added Figure : Power stage schematic Doc ID 77 Rev 5/6
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