MIC2208 MICREL [Micrel Semiconductor], MIC2208 Datasheet
MIC2208
Available stocks
Related parts for MIC2208
MIC2208 Summary of contents
Page 1
... The MIC2208 operates from 2.7V to 5.5V input and the output can be adjusted down to 1V. The devices can operate with a maximum duty cycle of 100% for use in low-dropout conditions. The MIC2208 is available in the exposed pad 3mm x 3mm MLF-12L package with a junction operating range from –40°C to +125°C. Typical Application MLF and MicroLeadFrame are trademarks of Amkor Technology Micrel, Inc • ...
Page 2
... Ordering Information Part Number MIC2208YML . Pin Configuration Pin Description Pin Number Pin Name 1,12 SW 2,11 VIN 3,10 PGND 4 SGND 5 BIAS COMP PGOOD EP GND September 2005 Output Junction Temp. Range (1) Voltage Adj. –40° to +125° VIN 2 11 PGND 3 10 SGND 4 9 BIAS ...
Page 3
Absolute Maximum Ratings Supply Voltage (V ) ...............................-0.3V to +6V IN Output Switch Voltage (V ) .....................-1V to +6V SW Output Switch Current (I ) ................................. 10A SW Logic Input Voltage (V )......................... -0. Storage Temperature (T ...
Page 4
... IN 0.9900 TEMPERATURE (°C) 4 MIC2207 2.5V Efficiency OUT 0.5 1 1.5 2 2.5 3 OUTPUT CURRENT (A) MIC2208 1.5V Efficiency OUT 3. 0.5 1 1.5 2 2.5 3 OUTPUT CURRENT (A) MIC2208 1.2V Efficiency OUT 4. 5.5V 5V ...
Page 5
Feedback Voltage vs. Supply Voltage 1.2 1.0 0.8 0.6 0.4 0 SUPPLY VOLTAGE (V) RDSON vs. Temperature 160 140 120 100 3. TEMPERATURE (°C) Max. Continuous Current ...
Page 6
... Functional Diagram VIN VIN BIAS Enable and EN Control Logic September 2005 PWM Control Bias, UVLO, Thermal Shutdown SGND MIC2208 Block Diagram 6 P-Channel Current Limit HSD SW SW COMP FB Soft EA Start 1.0V PGOOD 1.0V PGND M9999-092905 www.micrel.com ...
Page 7
Functional Characteristics Continuous Operation 3. 1V@1A OUT TIME (200ns/di v.) Transient Respons 3.3V. 1V 200m A IN TIME (100µs/di v.) Power Good V = 3.3V IN TIME (100µs/di ...
Page 8
... Please refer to layout recommendations. BIAS The bias (BIAS) provides power to the internal reference and control sections of the MIC2208 Ohm resistor from VIN to BIAS and a 0.1uF from BIAS to SGND is required for clean operation. EN The enable pin provides a logic level control of the output ...
Page 9
... Applications Information The MIC2208 PWM non-synchronous buck regulator. By switching an input voltage supply, and filtering the switched voltage through an Inductor and capacitor, a regulated DC voltage is obtained. Figure 1 shows a simplified example of a non-synchronous buck converter. Figure 1. For a non-synchronous buck converter, there are two ...
Page 10
... DC voltage, but to see actual operation (with ringing and all) refer to the functional characteristics. Discontinuous mode of operation has the advantage over full PWM in that at light loads, the MIC2208 will skip pulses as nessasary, reducing gate drive losses, drastically improving light load efficiency. Efficiency Considerations Calculating the efficiency is as simple as measuring power out and dividing it by the power in ...
Page 11
... ESR and ESL. Please refer to layout recommendations for proper layout of the input capacitor. Inductor Selection The MIC2208 is designed for use with a 1µH inductor. Proper selection should ensure the inductor can handle the maximum average and peak currents required by the load. Maximum current ratings of the inductor are generally given in two methods ...
Page 12
... The MIC2208 utilizes voltage mode compensation and has the error amplifier pin (COMP) pinned out to allow compensated using external components. This allows the MIC2208 to be stable with a wide range of inductor and capacitor values. TYPE II compensation Type II compensation can be expressed as pole- zero-pole ...
Page 13
... For 1.5 V OUT 150 k Ω 1% 0402 For 1.2 V OUT Open For 1.0 V OUT 499K Ω 1% 0402 resistor 10 Ω 1% 0402 resistor 10K Ω 1% 0402 resistor 1MHz 3A Buck Regulator 13 MIC2208 Manufacturer TDK Murata AVX AVX AVX AVX Vishay Semi TDK Wurth Electronik Vishay Dale ...
Page 14
... Inductor 12mOhm 7.3mm(L)x7.3mm(W)x3.2mm(H) 1uH Inductor 17.5m Ω ( L)6.47mmx(W)6.86mmx(H) 1.8mm 49.9K Ω 1% 0402 resistor 14 Type III Open Loop Gain Response Dominant Pole LC Frequency Zero Zero 20dB/Decade Frequency (Hz) MIC2208 Manufacturer TDK Murata AVX AVX AVX TDK Murata AVX Vishay VT Vishay Semi TDK ...
Page 15
... CRCW04024991F R5 CRCW040210R0F R6 CRCW04021002F U1 MIC2208BML Loop Stability and Bode Analysis Bode analysis is an excellent way to measure small signal stability and loop response in power supply designs. Bode analysis monitors gain and phase of a control loop. This is done by breaking the feedback loop and injecting a signal into the feedback node and comparing the injected signal to the output signal of the control loop ...
Page 16
The one disadvantage to using the op- amp injection method, that ...
Page 17
A good approximation for transient response can be calculated from determining the frequency of the load step in amps per second; A/sec = f π 2 Then, determine the output impedance by looking ...
Page 18
Package Information MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no ...
Page 19
Revision History Date Edits by: 3-30-05 Martin Galinski 6-16-05 Martin Galinski September 2005 19 Revision Number M9999-092905 www.micrel.com ...