Datasheet LT8625S (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 18V/8A Step-Down Silent Switcher 3 with Ultralow Noise Reference |
| Pages / Page | 39 / 1 — FEATURES. DESCRIPTION. Silent Switcher. 3 Architecture. Ultralow RMS … |
| File Format / Size | PDF / 4.9 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Silent Switcher. 3 Architecture. Ultralow RMS Noise (10Hz to 100kHz): 4μVRMS
Model Line for this Datasheet
Text Version of Document
LT8625S 18V/8A Step-Down Silent Switcher 3 with Ultralow Noise Reference
FEATURES DESCRIPTION
n
Silent Switcher
®
3 Architecture
The LT®8625S synchronous step-down regulator features n
Ultralow RMS Noise (10Hz to 100kHz): 4μVRMS
third-generation Silent Switcher technology which is n
Ultralow Spot Noise: 4nV/√Hz at 10kHz
uniquely designed to combine an ultralow noise reference n
Ultralow EMI Emissions on Any PCB
with Silent Switcher architecture in order to achieve both n
Internal Bypass Capacitors Reduce Radiated EMI
high efficiency and excellent wideband noise performance. n
High Efficiency at High Frequency
The innovative ultralow noise architecture provides excep- n
Ultrafast Transient Response: 1μs
tional low frequency (0.1Hz to 100kHz) output noise per- n
Fast Minimum Switch On-Time: 15ns
formance in a switching regulator. The output voltage can n
Input Voltage Range: 2.7V to 18V
be programmed with a single resistor, resulting in virtual y n
Output Voltage Range: 0V to (PVIN - 0.5V)
constant output noise independent of output voltage. n
8A Maximum Continuous Output Current
n
Precision Reference: ± 0.8% Over Temperature
Silent Switcher architecture minimizes EMI emissions while
with Remote Sense
delivering high efficiency at high switching frequencies. n Supports Dynamic Output Voltage Control The LT8625S is ideal for high current, noise sensitive n PolyPhase® Operation: Up to 12 Phases applications which benefit from the high efficiency of a n Forced Continuous Mode Capability synchronous switching regulator. n Adjustable and Synchronizable: 300kHz to 4MHz n
MAX EXPOSED INTV
Programmable Power Good
CC PACKAGE SIZE TEMP BACK CAPACITOR
n Small 20-Lead 4mm × 3mm LQFN Package LT8625S 4mm × 3mm 125°C No Internal LT8625SP 4mm × 3mm 150°C Yes External
APPLICATIONS
LT8625SP-1 4mm × 4mm 150°C Yes External n RF Power Suppliers: PLLs, VCOs, Mixers, LNAs, PAs Note: The LT8625SP-1 (8A) is Pin-to-Pin Compatible with the LT8627SP (16A). n High Speed/High Precision ADCs/DACs n Low Noise Instrumentation All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8823345.
TYPICAL APPLICATION 12VIN to 1 VOUT Efficiency
100 6.4 0.33µH V SV V OUT IN = 3.3V 1MHz IN PVIN SW 1V 2MHz 95 5.6 2.7V TO 18V 10µF SV 8A 3MHz IN OUTS 4MHz EN/UVLO 90 4.8 POWER LOSS (W) LT8625S 49.9k 85 4.0 VC 80 EFFICIENCY 3.2 1k SET PGFB 100µF 75 2.4 EFFICIENCY (%) 10k RT 4.7µF 49.9k 70 1.6 47k 2nF GND POWER LOSS 8625s TA1a 65 0.8 f 60 0 sw = 2MHz 1 2 3 4 5 6 7 8 LOAD CURRENT (A) 8625s TA01b Rev. B 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 Typical Application Related Parts
FEATURES DESCRIPTION
n
Silent Switcher
®
3 Architecture
The LT®8625S synchronous step-down regulator features n
Ultralow RMS Noise (10Hz to 100kHz): 4μVRMS
third-generation Silent Switcher technology which is n
Ultralow Spot Noise: 4nV/√Hz at 10kHz
uniquely designed to combine an ultralow noise reference n
Ultralow EMI Emissions on Any PCB
with Silent Switcher architecture in order to achieve both n
Internal Bypass Capacitors Reduce Radiated EMI
high efficiency and excellent wideband noise performance. n
High Efficiency at High Frequency
The innovative ultralow noise architecture provides excep- n
Ultrafast Transient Response: 1μs
tional low frequency (0.1Hz to 100kHz) output noise per- n
Fast Minimum Switch On-Time: 15ns
formance in a switching regulator. The output voltage can n
Input Voltage Range: 2.7V to 18V
be programmed with a single resistor, resulting in virtual y n
Output Voltage Range: 0V to (PVIN - 0.5V)
constant output noise independent of output voltage. n
8A Maximum Continuous Output Current
n
Precision Reference: ± 0.8% Over Temperature
Silent Switcher architecture minimizes EMI emissions while
with Remote Sense
delivering high efficiency at high switching frequencies. n Supports Dynamic Output Voltage Control The LT8625S is ideal for high current, noise sensitive n PolyPhase® Operation: Up to 12 Phases applications which benefit from the high efficiency of a n Forced Continuous Mode Capability synchronous switching regulator. n Adjustable and Synchronizable: 300kHz to 4MHz n
MAX EXPOSED INTV
Programmable Power Good
CC PACKAGE SIZE TEMP BACK CAPACITOR
n Small 20-Lead 4mm × 3mm LQFN Package LT8625S 4mm × 3mm 125°C No Internal LT8625SP 4mm × 3mm 150°C Yes External
APPLICATIONS
LT8625SP-1 4mm × 4mm 150°C Yes External n RF Power Suppliers: PLLs, VCOs, Mixers, LNAs, PAs Note: The LT8625SP-1 (8A) is Pin-to-Pin Compatible with the LT8627SP (16A). n High Speed/High Precision ADCs/DACs n Low Noise Instrumentation All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8823345.
TYPICAL APPLICATION 12VIN to 1 VOUT Efficiency
100 6.4 0.33µH V SV V OUT IN = 3.3V 1MHz IN PVIN SW 1V 2MHz 95 5.6 2.7V TO 18V 10µF SV 8A 3MHz IN OUTS 4MHz EN/UVLO 90 4.8 POWER LOSS (W) LT8625S 49.9k 85 4.0 VC 80 EFFICIENCY 3.2 1k SET PGFB 100µF 75 2.4 EFFICIENCY (%) 10k RT 4.7µF 49.9k 70 1.6 47k 2nF GND POWER LOSS 8625s TA1a 65 0.8 f 60 0 sw = 2MHz 1 2 3 4 5 6 7 8 LOAD CURRENT (A) 8625s TA01b Rev. B 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 Typical Application Related Parts
