DEMO MANUAL DC3033A LTC7817 Triple Output Synchronous Step-Up/Dual Step-Down Supply DESCRIPTION Demonstration circuit 3033A is a triple output syn- The main features of the board include rail tracking (buck chronous step-up/dual step-down supply featuring the channels only), an internal 5V linear regulator for bias, LTC 7817. The demonstration circuit is designed for two separated RUN pins for each output, a PGOOD signal (CH1 buck outputs 5V/10A, 3.3V/10A supplied by a boosted only), and a mode selector that allow the converter to run 10V output. Benefiting from this feature, the buck outputs in forced continuous mode (FCM), pulse-skipping (PSM) are able to maintain regulation over a wide input voltage or Burst Mode operation (BURST). Synchronization to range of 4.5V to 36V which is suitable for automotive or an external clock is also possible. The LTC7817 data other battery fed applications. Also, the demonstration sheet gives a complete description of these parts, opera- circuit uses a drop-in layout whereas the main buck circuit tion and application information. The data sheet must be components fit in an area of -inch by 1-inch, while the read in conjunction with this quick start guide for demo main boost circuit area is -inch by 1-inch. The pack- circuit3033A. age style for the LTC7817 is a 38-pin exposed padQFN. Design files for this circuit board are available. All registered trademarks and trademarks are the property of their respective owners. PERFORMANCE SUMMARY Specifications are at T = 25C A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Input Supply Range Operating (Note 1) 4.5 36 V IN Continuous Operation, I = 0A 10A, I = 0A 10A, Free Air 8 16 V OUT1 OUT2 V Output1 Voltage 3.2 3.3 3.4 V OUT1 V Output2 Voltage 4.9 5 5.1 V OUT2 V Output3 Voltage V = 4.5V 10V (Note 2) 9.8 10 10.2 V OUT3 IN I Output1 Current 10 A OUT1 I Output2 Current 10 A OUT2 I Output3 Current (Note 3) 10 A OUT3 f Switching Frequency 2200 kHz SW POUT/PIN Efficiency V = 12V, V = 3.3V, I = 10A, RUN2 = 0 88 % IN OUT1 OUT1 V = 12V, V = 5V, I = 10A, RUN1 = 0 91.4 % IN OUT2 OUT2 V = 12V, V = 5V, V = 3.3V, I = 10A, I = 10A 89.8 % IN OUT1 OUT2 OUT1 OUT2 V = 8V, V = 10V, I = 10A, RUN1,2 = 0 94.3 % IN OUT3 OUT3 Note 1: When 4.5V < V < 8V and 16V < V < 36V, only short time operation is allowed at maximum output power (free air). For example, run 10sec IN IN when V = 4.5V, 2min when V = 6V, 2min when V = 26V, 10sec when V = 36V or continuously operate for de-rated output current. IN IN IN IN Note 2: V follows V when V > V . OUT3 IN IN OUT3 Note 3: 10A Maximum output includes the current supplying CH1 and CH2. Rev. 0 1DEMO MANUAL DC3033A BOARD PHOTO Rev. 0 2