Overview
The MT3608 is a compact, high-efficiency PWM step-up DC-DC boost converter in a SOT-23-6 package. It accepts input voltages from 2 V to 24 V and regulates output up to 28 V at switch currents up to 2 A. Engineers use it widely in battery-powered systems, IoT nodes, wearables, and portable instruments. Its 1.2 MHz fixed switching frequency keeps external components small. Furthermore, its internal compensation and soft-start circuitry simplify design and reduce BOM count. LCSC Electronics stocks the MT3608 from multiple manufacturers, making it one of the most accessible boost converter ICs globally.
Key Takeaways
- Wide input range: The MT3608 boost converter operates from 2 V to 24 V input and regulates output up to 28 V.
- Small passives: Its 1.2 MHz PWM frequency allows inductors as small as 4.7 µH, minimising PCB footprint.
- Simplified design: Internal compensation eliminates the need for an external compensation network.
- Up to 93% efficiency: Peak conversion efficiency reaches 93%; the Schottky diode selection is the top efficiency lever.
- Built-in protection: The 2 A internal switch current limit provides inherent short-circuit protection.
- Programmable output: A two-resistor feedback divider sets output voltage; 1% resistors achieve ±2% accuracy.
- Compact package: The SOT-23-6 footprint (1.6 mm × 2.9 mm) suits standard reflow profiles at up to 260 °C.
What Is the MT3608 Boost Converter?
The MT3608 is a monolithic step-up switching regulator. It converts a lower DC input voltage to a higher regulated DC output. The device belongs to the inductive boost converter family and uses PWM to control an internal N-channel MOSFET switch. During switch on-time, the external inductor stores energy. During off-time, that energy transfers to the output capacitor and load via a Schottky diode.
Additionally, the MT3608 boost converter uses current-mode control with slope compensation. This ensures stable operation across the full duty-cycle range. The 0.6 V internal reference, combined with an external resistor divider, enables programmable output from approximately 2 V above the input up to 28 V. Manufacturers also reference this IC as a “step-up converter”, “boost regulator”, or simply “MT3608 IC” in datasheets and design forums.
Key Features and Advantages
1. Ultra-Low MT3608 Boost Converter Input Voltage
The MT3608 boost converter begins switching at input voltages as low as 2 V. This is critical for single-cell alkaline and NiMH battery applications. Most competing devices require 2.5 V or higher, which limits usable battery capacity. In contrast, the MT3608 operates even as a cell approaches end-of-life.
2. Fixed 1.2 MHz MT3608 Boost Converter PWM Operation
The MT3608 boost converter operates at a fixed 1.2 MHz switching frequency. This avoids AM radio band interference common in lower-frequency converters. It also simplifies EMC compliance and allows the use of sub-µH inductors in space-constrained layouts. Furthermore, the frequency is internally set and requires no external resistor or capacitor.
3. Integrated Soft-Start
An internal 1 ms soft-start ramp limits inrush current during power-up. This reduces stress on USB ports, thin battery cables, and upstream protection circuitry. As a result, it prevents premature overcurrent tripping at power-on.
4. Automatic Pulse-Skip in Light Load
At light loads, the MT3608 automatically transitions to pulse-skip modulation (PSM). This maintains high efficiency during low-current operation. It is especially valuable in IoT devices that alternate between active and deep-sleep modes, where quiescent current directly affects battery life.
5. Small BOM and Minimal External Components
A complete MT3608 power stage requires only six external components: one inductor, one Schottky diode, one input capacitor, one output capacitor, and two resistors. This minimal BOM reduces assembly cost, PCB area, and supply chain complexity. In addition, it is an important advantage for high-volume consumer and IoT product designs.
Technical Specifications
| Parameter | Symbol | Range / Value | Unit | Notes |
| Input Voltage | VIN | 2.0 – 24.0 | V | Boost topology; VIN must be < VOUT |
| Output Voltage | VOUT | Up to 28 | V | Set by external resistor divider; min ≈ VIN + 0.5 V |
| Switching Frequency | fSW | 1.2 | MHz | Fixed internal oscillator; ±15% tolerance |
| Switch Current Limit | ILIM | 2.0 (typ) | A | Peak current; triggers cycle-by-cycle limiting |
| Feedback Reference Voltage | VREF | 0.6 | V | ±2% accuracy over temperature |
| Quiescent Current | IQ | 0.9 (typ) | mA | No-load, switching active |
| Shutdown Current | ISD | < 1 | µA | EN pin pulled low |
| Peak Efficiency | η | ≥ 93 | % | Typical at VIN=3.7 V, VOUT=5 V, IOUT=0.5 A |
| Operating Temperature | TA | −40 to +85 | °C | Industrial temperature grade |
| Package | — | SOT-23-6 | — | JEDEC MO-178; 1.6 mm × 2.9 mm body |
| Enable Pin Logic High | VEN_H | 1.5 (min) | V | Threshold for turn-on |
| Minimum Inductor Value | LMIN | 4.7 (rec.) | µH | At 1.2 MHz; use 10–22 µH for high VOUT |
| Output Capacitor | COUT | 10 – 22 | µF | Low-ESR ceramic (X5R/X7R) recommended |
The MT3608 boost converter uses current-mode PWM control with internal slope compensation. This ensures stability at duty cycles above 50%, which is a common challenge at high VOUT/VIN ratios. The feedback formula is:
VOUT = 0.6 × (1 + R1/R2), where R2 is typically 100 kΩ.
The low 0.6 V reference allows fine-grained output setting with practical resistor values.
MT3608 Boost Converter Customisation and Configuration
MT3608 Boost Converter Output Voltage Setting
Output voltage is fully programmable through the R1/R2 feedback divider. For a 5 V output from a 3.7 V Li-ion input, set R2 to 100 kΩ and calculate R1 as 733 kΩ. Use the nearest standard E96 value: 732 kΩ. For a 12 V output, R1 = 1.9 MΩ. Use 1% tolerance metal-film resistors to achieve better than ±2% output accuracy. Also, place the divider close to the FB pin to minimise noise coupling.
MT3608 Boost Converter Inductor Selection
Inductor choice is the most influential MT3608 boost converter design decision after output voltage setting. At 1.2 MHz, a 10 µH inductor with DCR below 200 mΩ is recommended for general-purpose designs. Its saturation current rating must exceed the 2 A switch current limit. For high output voltages above 12 V or low input voltages below 2.5 V, increase inductance to 22 µH. This limits peak current ripple. Furthermore, shielded inductors reduce EMI and are preferred for consumer electronics.
MT3608 Boost Converter Enable Pin Control
The EN pin accepts a logic-level input with a 1.5 V threshold. Pulling EN low places the MT3608 boost converter in shutdown mode, drawing less than 1 µA. Consequently, a microcontroller GPIO can drive this pin for dynamic power sequencing. A supervisory circuit can also provide under-voltage lockout (UVLO). A 100 kΩ pull-up resistor to VIN is recommended if the EN pin is left unconnected.
MT3608 Boost Converter Schottky Diode Selection
The external Schottky rectifier diode carries the full output current during the switch-off phase. Select a diode with a forward voltage below 0.5 V at rated current and a reverse voltage rating above VOUT. Its average current rating must be at or above the maximum output current. For example, commonly paired devices include the SS24 (40 V, 2 A) and B5819W (40 V, 1 A) in SOD-123 packages. Higher reverse-voltage-rated diodes increase VF and reduce efficiency; therefore, select the minimum adequate rating.
Common Application Scenarios
Single-Cell Li-Ion to 5 V USB Power Bank
In this MT3608 boost converter scenario, the Li-ion cell voltage ranges from 3.0 V to 4.2 V. The USB 5 V rail must stay stable across the full battery discharge curve. Configure the MT3608 for VOUT = 5.1 V with a 22 µF ceramic output capacitor and an SS24 Schottky diode. The wide input range and automatic light-load pulse-skip maximise usable battery capacity. At 3.7 V input and 0.5 A output, measured efficiency is typically 91–93%.
Sensor Node VCC Rail from 2 × AA Batteries
Remote industrial sensor nodes run on alkaline batteries with an initial voltage of 3.0 V and an end-of-life voltage of 1.8 V. The microcontroller and radio require a stable 3.3 V rail even as the battery depletes below 2 V. The MT3608 boost converter configured for 3.3 V output starts up at as low as 2 V input. As a result, it extends usable battery life by up to 30% compared with converters requiring a 2.5 V minimum. A 22 µF ceramic output capacitor suppresses voltage ripple during radio transmission bursts.
LCD/OLED Bias Voltage Generation
Portable display modules in handheld test equipment often need a 9–15 V bias voltage. This voltage is frequently unavailable from the main system rail. Configure the MT3608 boost converter to 12 V output from a 5 V logic rail. It then drives the display bias node at 10–50 mA. Moreover, the 1.2 MHz switching frequency keeps magnetic components small and allows predictable EMI filtering with a single-stage LC output filter.
Programmable Laboratory Bench Power Module
For DIY and open-hardware bench tools, engineers need an adjustable voltage source from a fixed 5 V USB input. Pair the MT3608 boost converter with a digital potentiometer such as the MCP4131 on the feedback divider. This enables microcontroller-adjustable output voltage from 2 V to 24 V at up to 1 A. The EN pin provides software-controlled output enable and disable. In addition, a 100 µF polymer electrolytic capacitor paralleled with the 22 µF ceramic reduces load transient overshoot.
Manufacturing and Procurement
The MT3608 boost converter meets IPC-7711/7721 rework and IPC J-STD-001 soldering standards. Its SOT-23-6 package uses a standard reflow profile with a peak temperature of 260 °C (JEDEC J-STD-020). It is compatible with SAC305 and SAC405 lead-free solder alloys. The stencil aperture for SOT-23-6 pads is typically 0.25 mm × 0.65 mm at a 1:1 aperture ratio. Control paste volume carefully to prevent solder bridging on the 0.95 mm pitch.
For MT3608 boost converter PCB layout, keep the high-frequency switching loop as short and low-inductance as possible. Place the feedback divider away from this loop to minimise conducted noise at the FB pin. A ground plane directly below the IC reduces thermal resistance and EMI radiation.
LCSC Electronics stocks the MT3608 boost converter in tape-and-reel packaging. Prototyping reels have a standard MOQ of 100 pcs; production reels start at 3,000 pcs. Typical lead times from stock are 1–3 business days. The MT3608 is not AEC-Q100 qualified. For automotive applications, consider the MT3608A or equivalent AEC-Q100 qualified alternatives.
MT3608 Boost Converter Comparison
| Feature | MT3608 Boost Converter | XL6009 (Generic) | MT3608 Advantage |
| Min. Input Voltage | 2.0 V | 3.0 V | Better at low battery |
| Switching Frequency | 1.2 MHz | 400 kHz | Smaller passives, less EMI |
| Peak Switch Current | 2.0 A | 4.0 A | XL6009 higher power |
| Package | SOT-23-6 | SOP-8 / TO-263 | MT3608 smaller footprint |
| External Compensation | Not needed | Not needed | Equal |
| Typical Efficiency | 93% | 94% | Comparable |
| Feedback Voltage | 0.6 V | 1.25 V | MT3608 finer Vout adjust |
| Max Output Voltage | 28 V | 35 V | XL6009 better for 24 V+ |
| BOM Cost | Lower (SOT23) | Higher (larger pkg) | MT3608 cost advantage |
For designs with VIN below 2.5 V, high-frequency layout constraints, or strict PCB area budgets, the MT3608 boost converter is the preferred choice. For applications requiring output voltages above 24 V or switch currents above 2 A, evaluate the XL6009 or a synchronous boost converter such as the TPS61088 instead.
Frequently Asked Questions
How Do I Calculate the MT3608 Boost Converter Output Voltage Divider?
Use the formula: VOUT = 0.6 V × (1 + R1/R2). Set R2 to 100 kΩ. Calculate R1 as: R1 = R2 × ((VOUT / 0.6) − 1). For VOUT = 5 V, R1 = 100 kΩ × (8.33 − 1) = 733 kΩ. Use the nearest standard E96 value of 732 kΩ at 1% tolerance. Place both resistors as close to the FB pin as possible to minimise noise.
What Inductor Should I Use with the MT3608 Boost Converter?
Select an inductor with inductance of 10–22 µH for most applications. Its saturation current rating must be at or above 2 A. Keep DCR below 200 mΩ to minimise conduction losses. Also, use shielded construction to reduce EMI. Common choices include the Bourns SRR1260 and TDK VLF series. For VIN below 2.5 V, increase to 22 µH to limit peak inductor current.
What Is the Maximum Output Current of the MT3608 Boost Converter?
The MT3608 boost converter has a 2 A peak switch current limit. Maximum continuous output current depends on the conversion ratio, inductor value, and efficiency. At VIN = 3.7 V and VOUT = 5 V with a 10 µH inductor and 93% efficiency, expect approximately 1.0–1.2 A continuous output. Higher conversion ratios, such as 3.7 V to 12 V, reduce maximum output current to approximately 300–400 mA.
Is the MT3608 Boost Converter Suitable for Automotive Applications?
The MT3608 boost converter is rated for an industrial temperature range of −40 °C to +85 °C. It is not qualified to AEC-Q100 automotive reliability standards. For automotive applications requiring operation above 85 °C or AEC-Q100 Grade 1 qualification, consider the MT3608A or alternatives such as the TPS61032-Q1 or LM3478Q.
How Can I Improve MT3608 Boost Converter Efficiency?
Three actions deliver the highest MT3608 boost converter efficiency gains. First, select a Schottky diode with VF below 0.45 V at rated current; a high-VF diode alone can reduce efficiency by 3–5 percentage points. Second, use an inductor with DCR below 150 mΩ, since high DCR adds ohmic losses proportional to the square of inductor current. Third, use ceramic X5R/X7R output capacitors with ESR below 10 mΩ to minimise AC ripple losses.
Find What You Need on LCSC
Finding the right MT3608 boost converter and matching components is straightforward on LCSC. LCSC stocks the MT3608 alongside recommended Schottky diodes (SS24, B5819W), shielded inductors (Bourns SRR1260, TDK VLF series), and low-ESR ceramic capacitors — all filterable by specification and available for order in any quantity. Browse the full MT3608 boost converter catalogue and companion components at LCSC to browse MT3608 boost converter components: LCSC Electronics – Electronic Components Distributor.
