Datasheet LT8636, LT8637 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current |
| Seiten / Seite | 32 / 1 — FEATURES. DESCRIPTION. Silent Switcher. Architecture. Ultralow EMI … |
| Revision | C |
| Dateiformat / Größe | PDF / 2.7 Mb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Silent Switcher. Architecture. Ultralow EMI Emissions. Optional Spread Spectrum Modulation
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link to page 1 LT8636/LT8637 42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current
FEATURES DESCRIPTION
n
Silent Switcher
®
Architecture
The LT®8636/LT8637 synchronous step-down regulator n
Ultralow EMI Emissions
features Silent Switcher architecture designed to minimize n
Optional Spread Spectrum Modulation
EMI emissions while delivering high efficiency at high n
High Efficiency at High Frequency
switching frequencies. Peak current mode control with n
Up to 96% Efficiency at 1MHz, 12V
a 30ns minimum on-time allows high step-down ratios
IN to 5VOUT
n
Up to 95% Efficiency at 2MHz, 12V
even at high switching frequencies.
IN to 5VOUT
n
Wide Input Voltage Range: 3.4V to 42V
The LT8636’s ultralow 2.5µA quiescent current—with the n
5A Maximum Continuous, 7A Peak Transient Output
output in full regulation—enables applications requiring n
Ultralow Quiescent Current Burst Mode
®
Operation
highest efficiency at very small load currents. The LT8637 n
2.5µA IQ Regulating 12VIN to 3.3VOUT (LT8636)
has external compensation to enable current sharing and n
Output Ripple < 10mVP-P
fast transient response at high switching frequencies. A n
External Compensation: Fast Transient Response
CLKOUT pin enables synchronizing other regulators to
and Current Sharing (LT8637)
the LT8636/LT8637. n Fast Minimum Switch On-Time: 30ns Burst Mode operation enables ultralow standby current n Low Dropout Under All Conditions: 100mV at 1A consumption, forced continuous mode can control fre- n Forced Continuous Mode quency harmonics across the entire output load range, or n Adjustable and Synchronizable: 200kHz to 3MHz spread spectrum operation can further reduce EMI emis- n Output Soft-Start and Power Good sions. Soft-start and tracking functionality is accessed n Small 20-Lead 4mm × 3mm LQFN Package via the TR/SS pin, and an accurate input voltage UVLO n AEC-Q100 Qualified for Automotive Applications threshold can be set using the EN/UV pin.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8823345. n Automotive and Industrial Supplies n General Purpose Step-Down
TYPICAL APPLICATION 5V, 5A Step-Down Converter 12VIN to 5VOUT Efficiency
VIN 100 3.2 5.7V TO 42V EN/UV 95 2.8 4.7µF VIN VIN 1µF 1µF EFFICIENCY 90 2.4 GND GND POWER LOSS (W) 85 2.0 LT8636 BST 0.1µF 3.3µH 80 1.6 VOUT SW 5V 5A 75 1.2 BIAS EFFICIENCY (%) POWER LOSS INTVCC 10pF 1M 70 0.8 1µF 1MHz, L = 2.7µH RT FB 100µF 65 2MHz, L = 1.5µH 0.4 3MHz, L = 1µH 41.2k GND 243k 60 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 LOAD CURRENT (A) f 8636 TA01a SW = 1MHz 8636 TA01b Rev. C Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts
FEATURES DESCRIPTION
n
Silent Switcher
®
Architecture
The LT®8636/LT8637 synchronous step-down regulator n
Ultralow EMI Emissions
features Silent Switcher architecture designed to minimize n
Optional Spread Spectrum Modulation
EMI emissions while delivering high efficiency at high n
High Efficiency at High Frequency
switching frequencies. Peak current mode control with n
Up to 96% Efficiency at 1MHz, 12V
a 30ns minimum on-time allows high step-down ratios
IN to 5VOUT
n
Up to 95% Efficiency at 2MHz, 12V
even at high switching frequencies.
IN to 5VOUT
n
Wide Input Voltage Range: 3.4V to 42V
The LT8636’s ultralow 2.5µA quiescent current—with the n
5A Maximum Continuous, 7A Peak Transient Output
output in full regulation—enables applications requiring n
Ultralow Quiescent Current Burst Mode
®
Operation
highest efficiency at very small load currents. The LT8637 n
2.5µA IQ Regulating 12VIN to 3.3VOUT (LT8636)
has external compensation to enable current sharing and n
Output Ripple < 10mVP-P
fast transient response at high switching frequencies. A n
External Compensation: Fast Transient Response
CLKOUT pin enables synchronizing other regulators to
and Current Sharing (LT8637)
the LT8636/LT8637. n Fast Minimum Switch On-Time: 30ns Burst Mode operation enables ultralow standby current n Low Dropout Under All Conditions: 100mV at 1A consumption, forced continuous mode can control fre- n Forced Continuous Mode quency harmonics across the entire output load range, or n Adjustable and Synchronizable: 200kHz to 3MHz spread spectrum operation can further reduce EMI emis- n Output Soft-Start and Power Good sions. Soft-start and tracking functionality is accessed n Small 20-Lead 4mm × 3mm LQFN Package via the TR/SS pin, and an accurate input voltage UVLO n AEC-Q100 Qualified for Automotive Applications threshold can be set using the EN/UV pin.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8823345. n Automotive and Industrial Supplies n General Purpose Step-Down
TYPICAL APPLICATION 5V, 5A Step-Down Converter 12VIN to 5VOUT Efficiency
VIN 100 3.2 5.7V TO 42V EN/UV 95 2.8 4.7µF VIN VIN 1µF 1µF EFFICIENCY 90 2.4 GND GND POWER LOSS (W) 85 2.0 LT8636 BST 0.1µF 3.3µH 80 1.6 VOUT SW 5V 5A 75 1.2 BIAS EFFICIENCY (%) POWER LOSS INTVCC 10pF 1M 70 0.8 1µF 1MHz, L = 2.7µH RT FB 100µF 65 2MHz, L = 1.5µH 0.4 3MHz, L = 1µH 41.2k GND 243k 60 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 LOAD CURRENT (A) f 8636 TA01a SW = 1MHz 8636 TA01b Rev. C Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts