Datasheet LT8609S (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 42V, 2A/3A Peak Synchronous Step-Down Regulator with 2.5μA Quiescent Current |
| Seiten / Seite | 24 / 1 — FEATURES. DESCRIPTION. Silent Switcher. 2 Architecture. Ultralow EMI … |
| Revision | A |
| Dateiformat / Größe | PDF / 1.3 Mb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Silent Switcher. 2 Architecture. Ultralow EMI Emissions on Any PCB. Eliminates PCB Layout Sensitivity
Textversion des Dokuments
LT8609S 42V, 2A/3A Peak Synchronous Step-Down Regulator with 2.5µA Quiescent Current
FEATURES DESCRIPTION
n
Silent Switcher
®
2 Architecture
The LT®8609S is a compact, high efficiency, high speed n
Ultralow EMI Emissions on Any PCB
synchronous monolithic step-down switching regulator n
Eliminates PCB Layout Sensitivity
that consumes only 1.7µA of non-switching quiescent n
Internal Bypass Capacitors Reduce Radiated EMI
current. The LT8609S can deliver 2A of continuous cur- n
Optional Spread Spectrum Modulation
rent with peak loads of 3A (<1sec) to support applications n
Wide Input Voltage Range: 3.0V to 42V
such as GSM transceivers which require high transient n
Ultralow Quiescent Current Burst Mode
®
Operation:
loads. Top and bottom power switches are included with n
<2.5µA IQ Regulating 12VIN to 3.3VOUT
all necessary circuitry to minimize the need for external n
Output Ripple <10mVP-P
components. Low ripple Burst Mode operation enables n
High Efficiency 2MHz Synchronous Operation:
high efficiency down to very low output currents while n
>93% Efficiency at 1A, 12VIN to 5VOUT
keeping the output ripple below 10mVP-P. A SYNC pin n
2A Maximum Continuous Output, 3A Peak Transient
allows synchronization to an external clock, or spread
Output
spectrum modulation of switching frequencies for low n
Fast Minimum Switch-On Time: 45ns
EMI operation. Internal compensation with peak current n
Adjustable and Synchronizable: 200kHz to 2.2MHz
mode topology allows the use of small inductors and n Allows Use of Small Inductors results in fast transient response and good loop stabil- n Low Dropout ity. The EN/UV pin has an accurate 1V threshold and can n Peak Current Mode Operation be used to program VIN undervoltage lockout or to shut n Internal Compensation down the LT8609S reducing the input supply current to n Output Soft-Start and Tracking 1µA. A capacitor on the TR/SS pin programs the output n Small 16-Lead 3mm × 3mm LQFN Package voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% of the programmed output
APPLICATIONS
voltage as well as fault conditions. The LT8609S is avail- n able in a small 16-lead 3mm × 3mm LQFN package. General Purpose Step Down n Low EMI Step Down All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION 12VIN to 5VOUT Efficiency
100
5V, 2MHz Step Down
95 V 90 IN VIN 5.5V TO 40V 4.7µF ON OFF 85 EN/UV 2.2µH VOUT SYNC SW 5V 80 10pF 2A LT8609S 75 INTVCC 70 TR/SS PG 1M EFFICIENCY (%) RT FB 65 1µF 18.2k 182k 22µF GND 60 55 8609S TA01a fSW = 2MHz 50 0 0.50 1.00 1.50 2.00 2.50 IOUT (A) 8609S TA01b Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Silent Switcher
®
2 Architecture
The LT®8609S is a compact, high efficiency, high speed n
Ultralow EMI Emissions on Any PCB
synchronous monolithic step-down switching regulator n
Eliminates PCB Layout Sensitivity
that consumes only 1.7µA of non-switching quiescent n
Internal Bypass Capacitors Reduce Radiated EMI
current. The LT8609S can deliver 2A of continuous cur- n
Optional Spread Spectrum Modulation
rent with peak loads of 3A (<1sec) to support applications n
Wide Input Voltage Range: 3.0V to 42V
such as GSM transceivers which require high transient n
Ultralow Quiescent Current Burst Mode
®
Operation:
loads. Top and bottom power switches are included with n
<2.5µA IQ Regulating 12VIN to 3.3VOUT
all necessary circuitry to minimize the need for external n
Output Ripple <10mVP-P
components. Low ripple Burst Mode operation enables n
High Efficiency 2MHz Synchronous Operation:
high efficiency down to very low output currents while n
>93% Efficiency at 1A, 12VIN to 5VOUT
keeping the output ripple below 10mVP-P. A SYNC pin n
2A Maximum Continuous Output, 3A Peak Transient
allows synchronization to an external clock, or spread
Output
spectrum modulation of switching frequencies for low n
Fast Minimum Switch-On Time: 45ns
EMI operation. Internal compensation with peak current n
Adjustable and Synchronizable: 200kHz to 2.2MHz
mode topology allows the use of small inductors and n Allows Use of Small Inductors results in fast transient response and good loop stabil- n Low Dropout ity. The EN/UV pin has an accurate 1V threshold and can n Peak Current Mode Operation be used to program VIN undervoltage lockout or to shut n Internal Compensation down the LT8609S reducing the input supply current to n Output Soft-Start and Tracking 1µA. A capacitor on the TR/SS pin programs the output n Small 16-Lead 3mm × 3mm LQFN Package voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% of the programmed output
APPLICATIONS
voltage as well as fault conditions. The LT8609S is avail- n able in a small 16-lead 3mm × 3mm LQFN package. General Purpose Step Down n Low EMI Step Down All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION 12VIN to 5VOUT Efficiency
100
5V, 2MHz Step Down
95 V 90 IN VIN 5.5V TO 40V 4.7µF ON OFF 85 EN/UV 2.2µH VOUT SYNC SW 5V 80 10pF 2A LT8609S 75 INTVCC 70 TR/SS PG 1M EFFICIENCY (%) RT FB 65 1µF 18.2k 182k 22µF GND 60 55 8609S TA01a fSW = 2MHz 50 0 0.50 1.00 1.50 2.00 2.50 IOUT (A) 8609S TA01b Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts