Datasheet LTC3812-5 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 60V Current Mode Synchronous Switching Regulator Controller |
| Seiten / Seite | 34 / 1 — FEATURES. DESCRIPTION. High Voltage Operation: Up to 60V. Large 1Ω Gate … |
| Dateiformat / Größe | PDF / 412 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. High Voltage Operation: Up to 60V. Large 1Ω Gate Drivers. No Current Sense Resistor Required
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LTC3812-5 60V Current Mode Synchronous Switching Regulator Controller
FEATURES DESCRIPTION
The LTC3812-5 is a synchronous step-down switching n
High Voltage Operation: Up to 60V
regulator controller that can directly step down voltages n
Large 1Ω Gate Drivers
from up to 60V input, making it ideal for telecom and n
No Current Sense Resistor Required
automotive applications. The LTC3812-5 uses a constant n
Dual N-Channel MOSFET Synchronous Drive
on-time valley current control architecture to deliver very n Extremely Fast Transient Response low duty cycles with accurate cycle-by-cycle current limit n ±0.5% 0.8V Voltage Reference without requiring a sense resistor. n Programmable Soft-Start n Generates 5.5V Driver Supply A precise internal reference provides 0.5% DC accuracy. n Selectable Pulse-Skipping Mode Operation A high bandwidth (25MHz) error amplifi er provides very n Power Good Output Voltage Monitor fast line and load transient response. Large 1Ω gate driv- n Adjustable On-Time/Frequency: tON(MIN) < 100ns ers allow the LTC3812-5 to drive large power MOSFETs n Adjustable Cycle-by-Cycle Current Limit for higher current applications. The operating frequency n Undervoltage Lockout On Driver Supply is selected by an external resistor and is compensated for n Output Overvoltage Protection variations in VIN. A shutdown pin allows the LTC3812-5 to n Thermally Enhanced 16-Pin TSSOP Package be turned off reducing the supply current to <230μA. Integrated bias control generates gate drive power from
APPLICATIONS
the input supply during start-up and when an output short- n 48V Telecom and Base Station Power Supplies circuit occurs, with the addition of a small external SOT23 n Networking Equipment, Servers MOSFET. When in regulation, power is derived from the n Automotive and Industrial Control Systems output for higher effi ciency. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5847554, 6304066, 6476589, 6580258, 6677210, 6774611.
TYPICAL APPLICATION High Effi ciency High Voltage Step-Down Converter Effi ciency vs Load Current
V 100 IN 6V TO 60V RON 100k + C 110k IN V 22μF IN = 12V 95 M3 ION NDRV ZXMN- 100k 10A07F VIN = 42V PGOOD BOOST 90 VIN = 24V PGOOD LTC3812-5 M1 V L1 RNG TG EFFICIENCY (%) 0.1μF Si7850DP 4.7μH VOUT FCB SW 5V 85 5A EXTVCC RUN/SS INTVCC M2 80 1000pF ITH BG Si7850DP 10k 0 1 2 3 4 5 6 47pF + 200k D1 C LOAD CURRENT (A) 1μF OUT VFB MBR1100 270μF SGND PGND 38125 TA01b 5pF 1.89k 38125 TA01 38125fc 1
FEATURES DESCRIPTION
The LTC3812-5 is a synchronous step-down switching n
High Voltage Operation: Up to 60V
regulator controller that can directly step down voltages n
Large 1Ω Gate Drivers
from up to 60V input, making it ideal for telecom and n
No Current Sense Resistor Required
automotive applications. The LTC3812-5 uses a constant n
Dual N-Channel MOSFET Synchronous Drive
on-time valley current control architecture to deliver very n Extremely Fast Transient Response low duty cycles with accurate cycle-by-cycle current limit n ±0.5% 0.8V Voltage Reference without requiring a sense resistor. n Programmable Soft-Start n Generates 5.5V Driver Supply A precise internal reference provides 0.5% DC accuracy. n Selectable Pulse-Skipping Mode Operation A high bandwidth (25MHz) error amplifi er provides very n Power Good Output Voltage Monitor fast line and load transient response. Large 1Ω gate driv- n Adjustable On-Time/Frequency: tON(MIN) < 100ns ers allow the LTC3812-5 to drive large power MOSFETs n Adjustable Cycle-by-Cycle Current Limit for higher current applications. The operating frequency n Undervoltage Lockout On Driver Supply is selected by an external resistor and is compensated for n Output Overvoltage Protection variations in VIN. A shutdown pin allows the LTC3812-5 to n Thermally Enhanced 16-Pin TSSOP Package be turned off reducing the supply current to <230μA. Integrated bias control generates gate drive power from
APPLICATIONS
the input supply during start-up and when an output short- n 48V Telecom and Base Station Power Supplies circuit occurs, with the addition of a small external SOT23 n Networking Equipment, Servers MOSFET. When in regulation, power is derived from the n Automotive and Industrial Control Systems output for higher effi ciency. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5847554, 6304066, 6476589, 6580258, 6677210, 6774611.
TYPICAL APPLICATION High Effi ciency High Voltage Step-Down Converter Effi ciency vs Load Current
V 100 IN 6V TO 60V RON 100k + C 110k IN V 22μF IN = 12V 95 M3 ION NDRV ZXMN- 100k 10A07F VIN = 42V PGOOD BOOST 90 VIN = 24V PGOOD LTC3812-5 M1 V L1 RNG TG EFFICIENCY (%) 0.1μF Si7850DP 4.7μH VOUT FCB SW 5V 85 5A EXTVCC RUN/SS INTVCC M2 80 1000pF ITH BG Si7850DP 10k 0 1 2 3 4 5 6 47pF + 200k D1 C LOAD CURRENT (A) 1μF OUT VFB MBR1100 270μF SGND PGND 38125 TA01b 5pF 1.89k 38125 TA01 38125fc 1