Datasheet LT8631 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 100V, 1A Synchronous Micropower Step-Down Regulator |
| Seiten / Seite | 26 / 1 — FEATURES. DESCRIPTION. Ultrawide Input Voltage Range: 3V to 100V. Output … |
| Dateiformat / Größe | PDF / 375 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Ultrawide Input Voltage Range: 3V to 100V. Output Voltage Range: 0.8V to 60V
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LT8631 100V, 1A Synchronous Micropower Step-Down Regulator
FEATURES DESCRIPTION
n
Ultrawide Input Voltage Range: 3V to 100V
The LT®8631 is a current mode PWM step-down DC/DC n
Output Voltage Range: 0.8V to 60V
converter with internal synchronous switches that provide n
Internal Synchronous Switches
current for output loads up to 1A. The wide input range n
Low Ripple Burst Mode® Operation:
of 3V to 100V makes the LT8631 suitable for regulating
16µA IQ at 12VIN to 5VOUT Output Ripple <10mVP-P
power from a wide variety of sources, including automotive
7µA IQ at 48VIN to 5VOUT Output Ripple <10mVP-P
and industrial systems and 36V to 72V telecom supplies. n
Low Dropout: 99% Maximum Duty Cycle
Low ripple Burst Mode operation enables high efficiency n
Peak Current Mode Control
operation down to very low output currents while keeping n
Fixed Frequency Operation: 100kHz to 1MHz
the output ripple below 10mVP-P. Resistor programmable n
Synchronization Input
100kHz to 1MHz frequency range and synchronization ca- n
Programmable Undervoltage Lockout
pability enable optimization between efficiency and external n
Power Good Flag
component size. The soft-start feature controls the ramp n Flexible Output Voltage Tracking rate of the output voltage, eliminating input current surge n Short-Circuit Protection during start-up, while also providing output tracking. A n Low Shutdown Current: 5µA power good flag signals when the output voltage is within n Tolerates Pin Open/Short Faults ±7.5% of the regulated output. Undervoltage lockout can n Thermally Enhanced 20-Lead TSSOP with High be programmed using the EN/UV pin. Shutdown mode Voltage Lead Spacing reduces the total quiescent current to < 5µA. The LT8631 is available in a 20-lead TSSOP package with exposed pad
APPLICATIONS
for low thermal resistance and high voltage lead spacing. L n , LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks Automotive Supplies of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Telecom Supplies n Distributed Supply Regulation
TYPICAL APPLICATION 5V, 1A Step-Down Converter Efficiency vs Load Current
V 95 IN V F IN 6.5V TO 100V BST SW = 400kHz LT8631 90 2.2µF 0.1µF 22µH EN/UV SW 85 PG 80 75 IND 70 VOUT INTVCC VOUT 5V, 1A EFFICIENCY (%) 65 2.2µF 4.7pF 1M 60 VIN = 12V RT FB 55 VIN = 24V V 191k IN = 48V 25.5k SYNC/MODE TR/SS 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 GND LOAD CURRENT (A) 47µF 8631 TA01b 0.1µF FSW = 400kHz 8631 TA01a 8631fb For more information www.linear.com/LT8631 1
FEATURES DESCRIPTION
n
Ultrawide Input Voltage Range: 3V to 100V
The LT®8631 is a current mode PWM step-down DC/DC n
Output Voltage Range: 0.8V to 60V
converter with internal synchronous switches that provide n
Internal Synchronous Switches
current for output loads up to 1A. The wide input range n
Low Ripple Burst Mode® Operation:
of 3V to 100V makes the LT8631 suitable for regulating
16µA IQ at 12VIN to 5VOUT Output Ripple <10mVP-P
power from a wide variety of sources, including automotive
7µA IQ at 48VIN to 5VOUT Output Ripple <10mVP-P
and industrial systems and 36V to 72V telecom supplies. n
Low Dropout: 99% Maximum Duty Cycle
Low ripple Burst Mode operation enables high efficiency n
Peak Current Mode Control
operation down to very low output currents while keeping n
Fixed Frequency Operation: 100kHz to 1MHz
the output ripple below 10mVP-P. Resistor programmable n
Synchronization Input
100kHz to 1MHz frequency range and synchronization ca- n
Programmable Undervoltage Lockout
pability enable optimization between efficiency and external n
Power Good Flag
component size. The soft-start feature controls the ramp n Flexible Output Voltage Tracking rate of the output voltage, eliminating input current surge n Short-Circuit Protection during start-up, while also providing output tracking. A n Low Shutdown Current: 5µA power good flag signals when the output voltage is within n Tolerates Pin Open/Short Faults ±7.5% of the regulated output. Undervoltage lockout can n Thermally Enhanced 20-Lead TSSOP with High be programmed using the EN/UV pin. Shutdown mode Voltage Lead Spacing reduces the total quiescent current to < 5µA. The LT8631 is available in a 20-lead TSSOP package with exposed pad
APPLICATIONS
for low thermal resistance and high voltage lead spacing. L n , LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks Automotive Supplies of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Telecom Supplies n Distributed Supply Regulation
TYPICAL APPLICATION 5V, 1A Step-Down Converter Efficiency vs Load Current
V 95 IN V F IN 6.5V TO 100V BST SW = 400kHz LT8631 90 2.2µF 0.1µF 22µH EN/UV SW 85 PG 80 75 IND 70 VOUT INTVCC VOUT 5V, 1A EFFICIENCY (%) 65 2.2µF 4.7pF 1M 60 VIN = 12V RT FB 55 VIN = 24V V 191k IN = 48V 25.5k SYNC/MODE TR/SS 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 GND LOAD CURRENT (A) 47µF 8631 TA01b 0.1µF FSW = 400kHz 8631 TA01a 8631fb For more information www.linear.com/LT8631 1