Datasheet LT8608, LT8608B (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 42V, 1.5A Synchronous Step-Down Regulator with 2.5μA Quiescent Current |
| Seiten / Seite | 24 / 1 — FEATURES. DESCRIPTION. Wide Input Voltage Range: 3.0V to 42V. Ultralow … |
| Revision | D |
| Dateiformat / Größe | PDF / 2.7 Mb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Wide Input Voltage Range: 3.0V to 42V. Ultralow Quiescent Current Burst Mode. Operation:
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LT8608/LT8608B 42V, 1.5A Synchronous Step-Down Regulator with 2.5µA Quiescent Current
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 3.0V to 42V
The LT®8608 is a compact, high efficiency, high speed n
Ultralow Quiescent Current Burst Mode
®
Operation:
synchronous monolithic step-down switching regulator n
<2.5µA IQ Regulating 12VIN to 3.3VOUT
that consumes only 1.7µA of quiescent current. The LT8608 n
Output Ripple <10mVP-P
can deliver 1.5A of continuous current. Low ripple Burst n
High Efficiency 2MHz Synchronous Operation:
Mode operation enables high efficiency down to very low n
>92% Efficiency at 0.5A, 5VOUT from 12VIN
output currents while keeping the output ripple below n
1.5A Continuous Output Current
10mV. Internal compensation with peak current mode n
Fast Minimum Switch-On Time: 35ns
topology allows the use of small inductors and results in n
Adjustable and Synchronizable: 200kHz to 2.2MHz
fast transient response and good loop stability. The EN/ n
Spread Spectrum Frequency Modulation for Low EMI
UV pin has an accurate 1V threshold and can be used to n Allows Use of Small Inductors program VIN undervoltage lockout or to shut down the n Low Dropout LT8608. The PG flag signals when VOUT is within ±8.5% of n Peak Current Mode Operation the programmed output voltage as wel as fault conditions. n Accurate 1V Enable Pin Threshold The MSOP package includes a SYNC pin to synchronize n Internal Compensation to an external clock, or to select Burst Mode operation n Output Soft-Start and Tracking or pulse-skipping with or without spread-spectrum; the n Small 10-Lead MSOP Package or 8-Lead TR/SS pin programs soft-start or tracking. The DFN 2mm × 2mm DFN Package package omits these pins and can be purchased in pulse- skipping or Burst Mode operation varieties.
APPLICATIONS PACKAGE SYNC FUNCTIONALITY
n LT8608MSE MSE Programmable General Purpose Step Down n LT8608DFN DFN Burst Mode Operation Low EMI Step Down LT8608BDFN DFN Pulse-Skipping Mode All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION 12VIN to 5VOUT Efficiency IN OUT
100
5V, 2MHz Step-Down
95 90 VIN V 85 IN BST 5.5V TO 42V 4.7µF ON OFF EN/UV 0.1µF 2.2µH VOUT 80 SYNC SW 5V 75 10pF 1.5A LT8608 70 EFFICIENCY (%) INTVCC 65 TR/SS PG 1M 60 RT FB 1µF 18.2k 187k 22µF 55 f GND SW = 2MHz 50 8608 TA01a 0 0.25 0.50 0.75 1.00 1.25 1.50 IOUT (A) 8608 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 Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 3.0V to 42V
The LT®8608 is a compact, high efficiency, high speed n
Ultralow Quiescent Current Burst Mode
®
Operation:
synchronous monolithic step-down switching regulator n
<2.5µA IQ Regulating 12VIN to 3.3VOUT
that consumes only 1.7µA of quiescent current. The LT8608 n
Output Ripple <10mVP-P
can deliver 1.5A of continuous current. Low ripple Burst n
High Efficiency 2MHz Synchronous Operation:
Mode operation enables high efficiency down to very low n
>92% Efficiency at 0.5A, 5VOUT from 12VIN
output currents while keeping the output ripple below n
1.5A Continuous Output Current
10mV. Internal compensation with peak current mode n
Fast Minimum Switch-On Time: 35ns
topology allows the use of small inductors and results in n
Adjustable and Synchronizable: 200kHz to 2.2MHz
fast transient response and good loop stability. The EN/ n
Spread Spectrum Frequency Modulation for Low EMI
UV pin has an accurate 1V threshold and can be used to n Allows Use of Small Inductors program VIN undervoltage lockout or to shut down the n Low Dropout LT8608. The PG flag signals when VOUT is within ±8.5% of n Peak Current Mode Operation the programmed output voltage as wel as fault conditions. n Accurate 1V Enable Pin Threshold The MSOP package includes a SYNC pin to synchronize n Internal Compensation to an external clock, or to select Burst Mode operation n Output Soft-Start and Tracking or pulse-skipping with or without spread-spectrum; the n Small 10-Lead MSOP Package or 8-Lead TR/SS pin programs soft-start or tracking. The DFN 2mm × 2mm DFN Package package omits these pins and can be purchased in pulse- skipping or Burst Mode operation varieties.
APPLICATIONS PACKAGE SYNC FUNCTIONALITY
n LT8608MSE MSE Programmable General Purpose Step Down n LT8608DFN DFN Burst Mode Operation Low EMI Step Down LT8608BDFN DFN Pulse-Skipping Mode All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION 12VIN to 5VOUT Efficiency IN OUT
100
5V, 2MHz Step-Down
95 90 VIN V 85 IN BST 5.5V TO 42V 4.7µF ON OFF EN/UV 0.1µF 2.2µH VOUT 80 SYNC SW 5V 75 10pF 1.5A LT8608 70 EFFICIENCY (%) INTVCC 65 TR/SS PG 1M 60 RT FB 1µF 18.2k 187k 22µF 55 f GND SW = 2MHz 50 8608 TA01a 0 0.25 0.50 0.75 1.00 1.25 1.50 IOUT (A) 8608 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 Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts