ANP34063
Versatile buck-boost converter with wide input range (3V-40V), 1.5A switch current, and adjustable output voltage.
Product Overview
Description
The ANP34063 is a versatile buck-boost DC-DC converter capable of operating from input voltages above, below, or equal to the output voltage.
With a wide 3V to 40V input range and 1.5A switch current capability, it serves applications from battery-powered devices to industrial controls.
The device uses a simple external resistor divider for output voltage programming and requires minimal external components.
Product Series
ANP
Primary Application
Battery-powered equipment
Key Features
- Wide input voltage range (3V to 40V)
- Buck, boost, and buck-boost configurations
- 1.5A output switch current
- Adjustable output voltage
- Fixed 100kHz switching frequency
- Current limiting protection
- Thermal shutdown protection
- Low shutdown current (50μA)
Specifications
| Input Voltage | 3V to 40V |
|---|---|
| Output Voltage | 1.25V to 40V (adjustable) |
| Switch Current | 1.5A (maximum) |
| Switching Frequency | 100kHz (fixed) |
| Efficiency | Up to 85% |
| Quiescent Current | 2.5mA (operating), 50μA (shutdown) |
| Protection | Current limiting, thermal shutdown |
| Operating Temperature | -40°C to +85°C |
| Package | SOIC-8, DIP-8 |
Applications
Battery-powered equipment
Battery and charging management
Industrial control systems
Industrial automation and control
LED drivers
Motor drive and control systems
Power supply modules
Power conversion and supply
Automotive electronics
Automotive and EV electronics
Portable devices
Electronic system design
FAE Expert Insights
"The ANP34063 is a workhorse DC-DC converter that I've used in countless designs over the years. Its versatility in supporting buck, boost, and buck-boost topologies makes it invaluable for battery applications where input voltage varies above and below the output. The 3V-40V input range covers everything from single Li-ion cells to 24V industrial supplies. While the 100kHz switching frequency is lower than modern converters (resulting in larger inductors), it provides good efficiency and low EMI. I typically see 80-85% efficiency in buck mode and 75-80% in boost mode. The key to success with this device is proper inductor selection - use the datasheet formulas and add 30% margin for inductor value. For output capacitors, use low-ESR electrolytic or ceramic with sufficient ripple current rating."
Versatile buck-boost converter for battery and industrial applications
— Jennifer Liu, BeiLuo
Frequently Asked Questions
How do I calculate the inductor value for ANP34063?
Inductor value calculation for ANP34063: L_min = (V_out × (V_in - V_out)) / (V_in × f_sw × I_ripple). Where I_ripple is typically 20-30% of I_out. For example: V_in = 12V, V_out = 5V, I_out = 500mA, f_sw = 100kHz, I_ripple = 150mA (30%). L_min = (5 × (12-5)) / (12 × 100k × 0.15) = 35 / 180000 = 194μH. Use standard value 220μH with saturation current >1.5x I_out. For boost configuration, use L_min = (V_in² × (V_out - V_in)) / (V_out × f_sw × I_ripple × V_in). Always verify inductor saturation current rating exceeds peak switch current.
Calculate minimum inductance using formula. Use next standard value higher. Verify saturation current rating >1.5x output current.
What is the difference between buck, boost, and buck-boost configurations?
Buck (step-down): Output voltage is lower than input. Most efficient topology for voltage reduction. Use when V_in > V_out. Boost (step-up): Output voltage is higher than input. Use when V_in < V_out. Less efficient than buck due to higher switch current. Buck-boost (inverting): Output can be higher or lower than input, but polarity is inverted (negative output). Use when V_in varies above and below V_out. SEPIC and Ćuk are non-inverting buck-boost alternatives. ANP34063 supports all three configurations with different external component connections. Buck is most common and efficient, boost is used for battery-powered LED drivers, buck-boost for automotive applications with varying battery voltage.
Use buck when V_in always > V_out. Use boost when V_in always < V_out. Use buck-boost when V_in varies above and below V_out.
How do I set the output voltage for ANP34063?
Output voltage is set using a resistor divider from V_out to FB (feedback) pin to ground. Formula: V_out = 1.25V × (1 + R2/R1), where R1 is from FB to ground and R2 is from V_out to FB. For 5V output: Choose R1 = 1kΩ, then R2 = (5/1.25 - 1) × 1k = 3kΩ. Use 1% tolerance resistors for accuracy. Place resistors close to FB pin to minimize noise pickup. Add 100pF capacitor across R1 for stability. For adjustable output applications, use potentiometer for R2 with series fixed resistor for minimum value limit. Always verify output voltage regulation under minimum and maximum load conditions.
Calculate resistor values using formula. Use 1% resistors. Place close to FB pin. Add compensation capacitor for stability.
What causes poor efficiency in ANP34063 designs?
Common causes of poor efficiency: 1) Inductor too small - high ripple current increases losses. 2) Diode with high forward voltage - use Schottky diode with V_f < 0.5V. 3) Output capacitor ESR too high - causes ripple and heating. 4) Switching frequency too low - increases inductor and capacitor size without efficiency benefit. 5) Excessive quiescent current - use shutdown mode when not operating. To improve efficiency: Use proper inductor value, select low-V_f Schottky diode (1N5822 or similar), use low-ESR output capacitors, minimize trace lengths in high-current paths, and ensure adequate copper area for heat dissipation.
Check inductor value, diode V_f, and capacitor ESR. Use recommended components from datasheet. Optimize PCB layout.
Can ANP34063 be used for LED constant current drive?
Yes, ANP34063 can be configured for LED constant current drive by sensing LED current instead of output voltage. Connect current sense resistor (R_sense) in series with LED string, and connect FB pin to top of sense resistor. LED current: I_LED = 1.25V / R_sense. For 350mA LED current: R_sense = 1.25V / 0.35A = 3.57Ω (use 3.6Ω standard). Power in sense resistor: P = I² × R = 0.35² × 3.6 = 0.44W (use 1W resistor). For multiple LEDs with high forward voltage, use boost configuration. For automotive applications with varying battery voltage, use buck-boost. Add capacitor across sense resistor (100nF) to filter switching noise.
Calculate sense resistor using R = 1.25V / I_LED. Use appropriate power rating. Add filtering capacitor for noise reduction.