MIC2178-3.3BWM Micrel Inc, MIC2178-3.3BWM Datasheet
MIC2178-3.3BWM
Specifications of MIC2178-3.3BWM
Available stocks
Related parts for MIC2178-3.3BWM
MIC2178-3.3BWM Summary of contents
Page 1
... The output is protected with pulse-by-pulse current limiting and thermal shutdown. Undervoltage lockout turns the output off when the input voltage is less than 4.5V. The MIC2178 and is packaged in a 20-lead wide power SOIC package with an operating temperature range of –40°C to +85°C. ...
Page 2
... MIC2178 Ordering Information Standard* MIC2178BWM MIC2178-3.3BWM MIC2178-5.0BWM * Standard product will be supported as Pb-Free IAW PPCN #040004 effective 1-1-2005. Pin Configuration Pin Description Pin Number Pin Name VIN PGND 10 PWM 11 PWRGD COMP 14, 15, 16, 17 SGND 18 SYNC 19 BIAS 20 EN M9999-031805 Part Number Pb-Free Voltage ...
Page 3
... PWM mode, output not switching, 4.5V ≤ V ≤ 16.5V IN skip mode, output not switching, 4.5V ≤ V ≤ 16. 0V, 4.5V ≤ V ≤ 16. 16.5V IN MIC2178 [adj.]: V = 3.3V, I OUT MIC2178 [adj.]: V = 3.3V, OUT 5V ≤ V ≤ 16V, 10mA ≤ MIC2178-5. LOAD MIC2178-5.0: 6V ≤ V ≤ 16V, 10mA ≤ MIC2178-3 ...
Page 4
... PWRGD Threshold PWRGD Output Low PWRGD Off Leakage General Note: Devices are ESD sensitive. Handling precautions recommended. M9999-031805 Condition 5. 5.5V PWM MIC2178 [adj.]: measured at FB pin MIC2178-5.0: measured at FB pin MIC2178-3.3: measured at FB pin I = 1.0mA SINK V = 5.5V PWRGD 4 Micrel, Inc. Min ...
Page 5
... TEMPERATURE (°C) PWM-Mode Supply Current 12 OUTPUT 10 SWITCHING INPUT VOLTAGE (V) March 2005 Reference Voltage vs. Temperature 1.252 MIC2178 [adj.] 1.250 1.248 1.246 1.244 1.242 1.240 1.238 -60 - 120 150 TEMPERATURE (°C) Error-Amplifier Gain vs. Temperature 19.0 18.5 18.0 17.5 17.0 16.5 16.0 -60 -30 ...
Page 6
... Voltage PWM PWM/ Skip Mode Skip-Mode PWM Mode 10 Select Corrective Ramp SYNC 200kHz Stop Oscillator 18 Reset Pulse R C COMP MIC2178 [Adjustable] M9999-031805 Output I Control Logic I LIMIT Comp. I LIMIT Thresh. Voltage Skip-Mode Comp PWM Comp. V 1.245V REF SGND 14 ...
Page 7
... Shutdown Mode The MIC2178 has a low-current shutdown mode that is controlled by the enable input (EN). When a logic 0 is applied to EN, the MIC2178 is in shutdown mode, and its quiescent current drops to less than 5µA. Internal Bias Regulator An internal 3.3V regulator provides power to the MIC2178 control circuits. This internal supply is brought out to the BIAS pin for bypassing by an external 0.01µ ...
Page 8
... OUT multimedia circuits. There are two important items to be aware of when selecting PWM or skip mode. First, the MIC2178 can start-up only in PWM mode, and therefore requires a logic low at PWM during start-up. Second, in skip mode, the MIC2178 will supply a maximum load current of approximately 300mA, so the output will drop out of regulation when load current exceeds this limit ...
Page 9
... MIC2178 PWM-Mode Functional Diagram SYNC 200kHz Stop Oscillator 18 COMP MIC2178 [Adjustable] PWM-Mode Signal Path V SW Reset Pulse I LOAD I L1 Error Amp. Output I SENSE March 2005 Corrective Ramp Reset Pulse R Q PWM S Comp. Error Amp. V 1.245V REF SGND 4.5V to 16. VIN 100mΩ ...
Page 10
... MIC2178 Skip-Mode Functional Diagram Output Control Logic MIC2178 [Adjustable] Skip-Mode Signal Path OUT One-Shot Pulse I LIM 5mV REF – 5mV REF M9999-031805 4.5V to 16.5V VIN 100mΩ P-channel One Shot I SENSE Amp. I LIMIT Comp. I LIMIT Thresh. Voltage Skip-Mode Comp. V 1.245V REF ...
Page 11
... Application Information Feedback Resistor Selection (Adjustable Version) The output voltage is programmed by connecting an external resistive divider to the FB pin as shown in “MIC2178 Block Diagram.” The ratio determines the output voltage. To optimize efficiency during low output current operation, R2 should not be less than 20kΩ. However, to prevent feedback error due to input bias current at the FB pin, R2 should not be greater than 100kΩ ...
Page 12
... L1 Coiltronics CTX50-4P, DCR = 0.097 Ω 6.8nF L1 Coilcraft OUT 3.3V/1A C2 100µF 10V MIC2178-3.3BWM TPSE226M035R0300, ESR = 0.3Ω TPSD107M010R0100, ESR = 0.1Ω MBRS130LT3 DO3316P-473, DCR = 0.12Ω HM77-11003, DCR = 0.073Ω V OUT 5V/1A C2 100µF 10V MIC2178-5.0BWM TPSE226M035R0300, ESR = 0.3Ω ...
Page 13
... TPSE227M010R0100, ESR = 0.1Ω MBRS130LT3 HM77-18004, DCR = 0.075Ω V OUT 3.3V/1A C2 100µF 10V U1 Micrel MIC2178-3.3BWM C1 AVX TPSE226M035R0300, ESR = 0.3Ω C2 AVX TPSD107M010R0100, ESR = 0.1Ω C3 Z5UorX7R Ceramic Dielectric Material C4 X7RorNP0 Ceramic Dielectric Material D1 Motorola MBRS130LT3 L1 Coiltronics CTX33-3P, DCR = 0.077 Ω ...
Page 14
... DC DC ± 5V/500mA Regulator OUT 3.3V/1A C2 100µF 10V U1 Micrel MIC2178-3.3BWM C1 AVX TPSE226M035R0300, ESR = 0.3Ω C2 AVX TPSD107M010R0100, ESR = 0.1Ω C3 Z5UorX7R Ceramic Dielectric Material C4 X7RorNP0 Ceramic Dielectric Material D1 Motorola MBRS130LT3 Q1 Siliconix Si9435DY PMOS L1 Coiltronics CTX50-4P, DCR = 0.097 Ω L1 Coilcraft DO3316-473, DCR = 0.12Ω ...
Page 15
... MIC2178 Suggested Manufacturers List Inductors Capacitors Coilcraft AVX Corp. 1102 Silver Lake Rd. 801 17th Ave. South Cary, IL 60013 Myrtle Beach, SC 29577 tel: (708) 639-2361 tel: (803) 448-9411 fax: (708) 639-1469 fax: (803) 448-1943 Coiltronics Sanyo Video Components Corp. 6000 Park of Commerce Blvd. ...