1A 200kHz SuperSwitcher™ Buck Regulator
Features
• SOIC-8 package with up to 1.3A output current
• All surface mount solution
• Only 4 external components required
• Fixed 200kHz operation
• 3.3V, 5V, and adjustable output versions
• Internally compensated with fast transient response
• Wide 4V to 34V operating input voltage range
• Less than 2µA typical shutdown-mode current
• Up to 90% efficiency
• Thermal shutdown
• Overcurrent protection
Applications
• Simple 1A high-efficiency step-down (buck) regulator
• Replacement of TO-220 and TO-263 designs
• Efficient pre-regulator (5V to 2.5V, 12V to 3.3V, etc.)
• On-card switching regulators
• Positive-to-negative converter (inverting buck-boost)
• Simple battery charger
• Negative boost converter
• Higher output current regulator using external FET
General Description
The MIC4680 SuperSwitcher™ is an easy-to-use fixed or adjustable
output voltage step-down (buck) switch-mode voltage regulator. The
200kHz MIC4680 achieves up to 1.3A of continuous output current
over a wide input range in a 8-pin SOIC.
The MIC4680 is available in 3.3V and 5V fixed output versions or
adjustable output down to 1.25V.
The MIC4680 has an input voltage range of 4V to 34V, with excellent
line, load, and transient response. The regulator performs
cycle-by-cycle current limiting and thermal shutdown for protection
under fault conditions. In shutdown mode, the regulator draws less
than 2µA of standby current.
The MIC4680 SuperSwitcher™ regulator requires a minimum number of
external components and can operate using a standard series of
inductors and capacitors. Frequency compensation is provided
internally for fast transient response and ease of use.
Absolute Maximum Ratings(1)
Supply Voltage (VIN) (3)
..................................................+38V
Shutdown Voltage (VSHDN)............................. –0.3V to +38V
Steady-State Output Switch Voltage (VSW)....................–1V
Feedback Voltage [Adjustable] (VFB) ...........................+12V
Storage Temperature (Ts) .........................–65°C to +150°C
Operating Ratings(2)
Supply voltage (VIN) (4)....................................... +4V
to +34V
Junction Temperature (TJ) .......................................
+125°C
Package Thermal Resistance(6) SIOC
(θJA).........................63°C/W
Pin Description
| Pin Number | Pin Name | Pin Function |
| 1 | SHDN | Shutdown (Input): Logic low enables regulator. Logic high
(>1.6V) shuts down regulator. |
| 2 | VIN | Supply Voltage (Input): Unregulated +4V to +34V supply voltage. |
| 3 | SW | Switch (Output): Emitter of NPN output switch. Connect to external
storage inductor and Shottky diode. |
| 4 | FB | Feedback (Input): Connect to output on fixed output voltage
versions, or to 1.23V-tap of voltage-divider network for adjustable
version |
| 5 – 8 | GND | Ground |
