DC2897A: LTC7819 Low IQ, Triple Output Synchronous Step-Down Supply
Demo manual for the DC2897A featuring the LTC7819, a triple output synchronous step-down supply providing 3.3V, 8.5V, and 5V outputs from a 10V-36V input.
Overview
The DC2897A demonstration circuit showcases the LTC7819, a low IQ, triple output synchronous step-down controller designed for high-efficiency power conversion. The circuit provides three regulated outputs: 3.3V at 12A, 8.5V at 10A, and 5.0V at 12A, operating over an input voltage range of 10V to 36V. It features a default switching frequency of 380kHz and supports multiple light-load operating modes, including Burst Mode, pulse-skipping, and forced continuous mode. The design includes optional spread spectrum modulation for EMI reduction, external clock synchronization via the PLLIN pin, and EXTVCC biasing to improve efficiency. The board is configured with 3mΩ sense resistors for current sensing but provides footprints for optional DCR sensing. It also supports paralleling two or three channels for higher current demands.
Use Cases
- Automotive Systems
- Industrial Equipment
- Transportation Infrastructure
- Military and Avionics Systems
- High Efficiency DC-DC Conversion
Topics
Referenced Parts
DFLS1100Q-7
Diodes Inc.
DIODE, SCHOTTKY, 100V, 1A, POWERDI-123, AEC-Q101
KRL5025E-C-R003-F-T1
Susumu
RES., 0.003, 0Ω, 1%, 2W, 2010 LONG-SIDE TERM, METAL, SENSE, AEC-Q200
62000311121
Wurth Elektronik
CONN., HDR, MALE, 1×3, 2mm, VERT, ST, THT, NO SUBS. ALLOWED
62000621121
Wurth Elektronik
CONN., HDR, MALE, 2×3, 2mm, VERT, ST, THT
AEC-Q200
Panasonic
27 1 R6 RES., 1k, 5%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ3GEYJ102V
AEC-Q200
Panasonic
22 1 R31 RES., 10k, 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ3EKF1002V
AEC-Q200
Vishay
RES., 0Ω, 1/10W, 0603, AEC-Q200 VISHAY, CRCW06030000Z0EA; CRCW06030000Z0EB
AEC-Q200
Vishay
29 4 R7, R34, R37, R63 RES., 100k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW0603100KFKEA
AEC-Q200
Vishay
24 1 R43 RES., 105k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW0603105KFKEA
AEC-Q200
Vishay
20 1 R20 RES., 0Ω, 1/4W, 1206, AEC-Q200 VISHAY, CRCW12060000Z0EA
2mm
Wurth Elektronik
6 3 XJP1, XJP2, XJP4 CONN., SHUNT, FEMALE, 2-POS, 2mm WURTH ELEKTRONIK, 60800213421
| 06035A102KAT2A | AVX | CAP., 1000pF, C0G, 50V, 10%, 0603 |
| 06035C104KAT2A | AVX | CAP., 0.1μF, X7R, 50V, 10%, 0603 |
| 06035C221KAT2A | AVX | CAP., 220pF, X7R, 50V, 10%, 0603 |
| 06035C222KAT2A | AVX | CAP., 2200pF, X7R, 50V, 10%, 0603 |
| 06035C470KAT2A | AVX | CAP., 47pF, X7R, 50V, 10%, 0603 |
| 0603ZC105KAT2A | AVX | CAP., 1μF, X7R, 10V, 10%, 0603 |
| 12105C475KAT2A | AVX | CAP., 4.7μF, X7R, 50V, 10%, 1210 |
| 1210ZC476KAT2A | AVX | CAP., 47μF, X7R, 10V, 10%, 1210 |
| CR0603-FX-1333ELF | Bourns | RES., 133k, 1%, 1/10W, 0603 |
| XAL1010-222MEB | Coilcraft | IND., 2.2μH, PWR., 20%, 11.8mm × 10.5mm SMD, AEC-Q200 |
| XAL1010-332MEB | Coilcraft | IND., 3.3μH, PWR., 20%, 25A, 4.10mΩ, 11.8mm × 10.5mm, XAL1010, AEC-Q200 |
| BSC022N04LS6 | Infineon | XSTR., MOSFET, N-CH, 40V, 100A, TDSON-8 FL |
| BSC059N04LS6 | Infineon | XSTR., MOSFET, N-CH, 40V, 59A, TDSON-8 FL |
| C0805C475K8PACTU | Kemet | CAP., 4.7μF, X5R, 10V, 10%, 0805 |
| GRM1885C1H103JA01D | Murata | CAP., 0.01μF, C0G, 50V, 5%, 0603 |
| 10TPF150ML | Panasonic | CAP., 150μF, TANT. POSCAP, 10V, 20%, 7343, D3L |
| 6TCF470MAH | Panasonic | CAP., 470μF, TANT, POSCAP, 6.3V, 20%, 7343, 10mΩ, TCF |
| EEEFK1H221GP | Panasonic | CAP., 220μF, ALUM ELECT, 50V, 20%, 10mm × 10.2mm, RADIAL, SMD, AEC-Q200 |
| ERJ3EKF1002V | Panasonic | RES., 10k, 1%, 1/10W, 0603, AEC-Q200 |
| ERJ3EKF4991V | Panasonic | RES., 4.99k, 1%, 1/10W, 0603 |
| ERJ3GEYJ102V | Panasonic | RES., 1k, 5%, 1/10W, 0603, AEC-Q200 |
| CRCW06030000Z0EA | Vishay | RES., 0Ω, 1/10W, 0603, AEC-Q200 |
| CRCW0603100KFKEA | Vishay | RES., 100k, 1%, 1/10W, 0603, AEC-Q200 |
| CRCW0603105KFKEA | Vishay | RES., 105k, 1%, 1/10W, 0603, AEC-Q200 |
| CRCW060310R0FKEA | Vishay | RES., 10Ω, 1%, 1/10W, 0603 |
| CRCW060313K7FKEA | Vishay | RES., 13.7k, 1%, 1/10W, 0603, AEC-Q200 |
| CRCW12060000Z0EA | Vishay | RES., 0Ω, 1/4W, 1206, AEC-Q200 |
| LTC7819RUJ#PBF | Analog Devices | IC, SYN. STEP-DOWN CONVERTER, 40-PIN QFN |
| NRC06F1004TRF | NIC | RES., 1M, 1%, 1/10W, 0603, AEC-Q200 |
| NRC06F2002TRF | NIC | RES., 20k, 1%, 1/10W, 0603 |
| DFLS1100Q-7 | Diodes Inc. | DIODE, SCHOTTKY, 100V, 1A, POWERDI-123, AEC-Q101 |
| KRL5025E-C-R003-F-T1 | Susumu | RES., 0.003, 0Ω, 1%, 2W, 2010 LONG-SIDE TERM, METAL, SENSE, AEC-Q200 |
| 62000311121 | Wurth Elektronik | CONN., HDR, MALE, 1×3, 2mm, VERT, ST, THT, NO SUBS. ALLOWED |
| 62000621121 | Wurth Elektronik | CONN., HDR, MALE, 2×3, 2mm, VERT, ST, THT |
| AEC-Q200 | Panasonic | 27 1 R6 RES., 1k, 5%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ3GEYJ102V |
| AEC-Q200 | Panasonic | 22 1 R31 RES., 10k, 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ3EKF1002V |
| AEC-Q200 | Vishay | RES., 0Ω, 1/10W, 0603, AEC-Q200 VISHAY, CRCW06030000Z0EA; CRCW06030000Z0EB |
| AEC-Q200 | Vishay | 29 4 R7, R34, R37, R63 RES., 100k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW0603100KFKEA |
| AEC-Q200 | Vishay | 24 1 R43 RES., 105k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW0603105KFKEA |
| AEC-Q200 | Vishay | 20 1 R20 RES., 0Ω, 1/4W, 1206, AEC-Q200 VISHAY, CRCW12060000Z0EA |
| 2mm | Wurth Elektronik | 6 3 XJP1, XJP2, XJP4 CONN., SHUNT, FEMALE, 2-POS, 2mm WURTH ELEKTRONIK, 60800213421 |