Document
MIC2295
High Power Density 1.2A Boost Regulator
General Description
The MIC2295 is a 1.2Mhz, PWM dc/dc boost switching regulator available in low profile Thin SOT23 and 2mm x 2mm MLF package options. High power density is achieved with the MIC2295’s internal 34V / 1.2A switch, allowing it to power large loads in a tiny footprint. The MIC2295 implements constant frequency 1.2MHz PWM current mode control. The MIC2295 offers internal compensation that offers excellent transient response and output regulation performance. The high frequency operation saves board space by allowing small, low-profile external components. The fixed frequency PWM scheme also reduces spurious switching noise and ripple to the input power source. The MIC2295 is available in a low-profile Thin SOT23 5-lead package and a 2mm x2mm 8-lead MLF leadless package. The 2mm x 2mm MLF package option has an output over-voltage protection feature. The MIC2295 has an operating junction temperature range of –40°C to +125°C
Features
• • • • • • • • • • • • • 2.5V to 10V input voltage range Output voltage adjustable to 34V 1.2A switch current 1.2MHz PWM operation Stable with small size ceramic capacitors High efficiency Low input and output ripple <1mA shutdown current UVLO Output over-voltage protection (MIC2295BML) Over temperature shutdown Thin SOT23-5 package option 2mm x 2mm leadless 8-lead MLF package option –40oC to +125oC junction temperature range
•
Applications
• Organic EL power supplies • 3.3V to 5V/500mA conversion • TFT-LCD bias supplies • Flash LED drivers • Positive and negative output regulators • SEPIC converters • Positive to negative Cuk converters • 12V supply for DSL applications Multi-output dc/dc converters
10µH
VOUT 15V/100mA
L1 10µH
VOUT 5V/500mA
VIN 1-Cell Li Ion 3V to 4.2V
MIC2295BML SW OVP FB EN VIN C1 2.2µF AGND PGND R2 9.01K
MIC2295 BD5
R1 100k 2.2µF
VIN VIN 1-Cell Li Ion EN C1 2.2µF
SW FB
R1 10k 10µF R2 3.3k
GND
MLF and MicroLeadFrame is a trademark of Amkor Technology
July 2004
M9999-072204 (408) 955-1690
Micrel
MIC2295
Ordering Information
Part Number Standard Lead-Free Output Over Voltage Protection Marking Code Standard Lead-Free Thin SOT235 2mm x2mm MLF-8L Junction Temperature Range Package
MIC2295BD5 MIC2295BML
MIC2295YD5 MIC2295YML
34V
SVAA SXA
SVAA SXA
-40°C to 125°C
-40°C to 125°C
Pin Configuration
Pin Description
MIC2295BD5 Thin SOT-23-5 1 2 3 4 5 MIC2295BML 2x2 MLF-8L 7 6 3 2 1 Pin Name Pin Function
SW GND FB EN VIN OVP
5 4 8 EP July 2004
N/C AGND PGND GND
Switch Node (Input): Internal power BIPOLAR collector. Ground (Return): Ground. Feedback (Input): 1.24V output voltage sense node. VOUT = 1.24V ( 1 + R1/R2) Enable (Input): Logic high enables regulator. Logic low shuts down regulator. Supply (Input): 2.5V to 10V input voltage. Output Over-Voltage Protection (Input): Tie this pin to VOUT to clamp the output voltage to 34V maximum in fault conditions. Tie this pin to ground if OVP function is not required. No connect. No internal connection to die. Analog ground Power ground Ground (Return). Exposed backside pad. 2 M9999-052402 (408) 955-1690
Micrel
MIC2295
Absolute Maximum Rating (1)
Supply voltage (VIN) ……………………..… 12V Switch voltage (VSW) …………………… -0.3V to 34V Enable pin voltage (VEN) …………..……..…. -0.3 to VIN FB Voltage (VFB)……...………………………..…………6V Switch Current (ISW) ………………………..…..….. 2.5A Ambient Storage Temperature (TS) …. -65°C to +150°C ESD Rating(3)...………………………… ……..2KV
Operating Range (2)
Supply Voltage (VIN) …………………..…… 2.5V to 10V Junction Temperature Range (TJ) …… -40°C to +125°C Package Thermal Impedance 93°C/W JA 2x2 MLF-8L lead …………………… JA ThinSOT23-5 lead …………………… 256°C/W
Electrical Characteristics T =25 C, V
A o
IN
=VEN = 3.6V, VOUT = 15V, IOUT = 40mA, unless otherwise noted. Bold values
indicate -40°C TJ 125°C.
Symbol VIN VUVLO IVIN ISD VFB
Parameter Supply Voltage Range Under-Voltage Lockout Quiescent Current Shutdown Current Feedback Voltage
Condition
Min 2.5 1.8
Typ 2.1 2.8 0.1 1.24
VFB = 2V (not switching) VEN = 0V(4) (+/-1%) (+/-2%) (Over Temp) 1.227 1.215
Max 10 2.4 5 1 1.252
Units V V mA mA V
1.265 -450 0.04 1 1.5 nA % % % A mV mA V mA MHz V °C °C
IFB
Feedback Input Current Line Regulation Load Regulation
VFB = 1.24V 3V VIN 5V 5mA IOUT 40mA 85 Note 5 ISW = 1.2A VEN = 0V, VSW = 10V TURN ON TURN OFF VEN = 10V MIC2295BML only Hysteresis 1.2
DMAX ISW VSW ISW VEN IEN fSW VOVP Tj
Notes: 1.
Maximum Duty Cycle Switch Current Limit Switch Saturation Voltage Switch Leakage Current Enable Threshold Enable Pin Current Oscillator Frequency Output over-voltage protection Over-Temperature Threshold Shutdown
90 1.7 600 0.01
5 0.4 40 1.35 34
1.5 20 1.2 32 150 10
1.05 30
2. 3. 4. 5.
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of its operating ratings. The maximum allowable power dissipation is a function o.