LTC3112EFE#PBF - 15V, 2.5A Sync Buck-Boost DC/DC | Analog Devices
MPN： LTC3112EFE#PBF ✓ 啟用中LTC3112EFE#PBF 概覽
A buck-boost converter is a type of DC-DC switching regulator that can step up or step down an input voltage to produce a regulated output. It is essential in applications where the input voltage can vary above and below the desired output, such as with batteries that discharge over time. The LTC3112 belongs to the family of switching regulators, which are more efficient than linear regulators for large voltage differences, and it is a key component in power management ICs for portable and industrial devices.
Key features include a 2.5A continuous output current, a wide 2.7V to 15V input range, and an adjustable output from 2.5V to 14V. The device operates at a fixed frequency (typically 1.2MHz) and offers high efficiency across a broad load range. It includes internal synchronous switches, eliminating the need for external Schottky diodes, and provides low output ripple for noise-sensitive applications. The LTC3112 also features a shutdown mode that reduces quiescent current to microamperes, extending battery life in portable devices.
Technically, the LTC3112 uses a 4-switch architecture with a single inductor, which allows seamless transitions between buck, boost, and buck-boost modes. This design minimizes output voltage glitches during mode transitions, a common issue in traditional buck-boost converters. The device includes soft-start to limit inrush current, current mode control for fast transient response, and thermal shutdown protection. The exposed pad on the TSSOP package aids in heat dissipation, allowing the converter to deliver full 2.5A output without excessive junction temperature rise.
Typical applications include generating 3.3V or 5V rails from 1, 2, or 3 Li-Ion cells, backup capacitor stacks, handheld inventory terminals, RF transmitters, 12V synchronous boost converters, multiple power input systems, LED lighting with current regulation, and 12V lead-acid battery to 12V conversion. The wide input range and high output current make it ideal for industrial, automotive, and portable electronics where input voltage varies significantly.
When designing with the LTC3112, ensure proper inductor selection (typically 2.2µH to 10µH) and adequate input/output capacitance to maintain stability and low ripple. The exposed pad must be soldered to a copper pour for thermal management. Also, consider the trade-off between efficiency and output ripple when choosing the operating mode.
直接替換替代品，適用於 LTC3112EFE#PBF — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LTC3112EFE#PBF （相同外形與佔位） — 差異在於 Operating Temperature Range, Switching Frequency, Function, Package.
LTC3112EFE#TRPBF
✅ 直接替換聯絡詢價
查看資料表 →LTC3112IFE#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC3115HFE-1#PBF
⚡ 相同封裝 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC3112EFE#PBF 最大額定值與電氣特性
| 功能 | Buck-Boost |
| 輸出類型 | Adjustable |
| 輸出電壓範圍 | 2.5V to 14V |
| 最大輸出電流 | 2.5A |
| 輸入電壓範圍 | 2.7V to 15V |
| 切換頻率 | 1.2MHz (typical) |
| 同步整流 | Yes |
| 輸出數量 | 1 |
| 封裝 | 20-TSSOP (0.173", 4.40mm Width) Exposed Pad |
| 安裝類型 | Surface Mount |
| 工作溫度範圍 | -40°C to +125°C |
| Quiescent Current (Shutdown) | 1µA (typical) |
| 軟啟動 | Yes |
| 過熱關機 | Yes |
| RoHS 狀態 | Compliant |
LTC3112EFE#PBF 腳位配置
| 腳位 1 | SW1 — Switch node connection for inductor |
| 腳位 2 | PVIN1 — Power input supply |
| 腳位 3 | PVIN2 — Power input supply |
| 腳位 4 | SHDN — Shutdown control (active low) |
| 腳位 5 | VIN — Input supply for internal circuitry |
| 腳位 6 | VOUT — Output voltage sense |
| 腳位 7 | FB — Feedback input for output regulation |
| 腳位 8 | VCC — Internal regulated supply |
| 腳位 9 | GND — Ground |
| 腳位 10 | GND — Ground |
| 腳位 11 | GND — Ground |
| 腳位 12 | GND — Ground |
| 腳位 13 | GND — Ground |
| 腳位 14 | GND — Ground |
| 腳位 15 | GND — Ground |
| 腳位 16 | GND — Ground |
| 腳位 17 | GND — Ground |
| 腳位 18 | GND — Ground |
| 腳位 19 | SW2 — Switch node connection for inductor |
| 腳位 20 | PVOUT — Power output supply |
典型應用
LTC3112EFE#PBF 適用於 6 應用s: Battery-Powered Portable Devices, Industrial Power Supplies, RF Transmitters and Power Amplifiers, LED Lighting with Current Regulation, Multiple Power Input Systems, Backup Capacitor Stack.
Battery-Powered Portable Devices
The LTC3112EFE#PBF is ideal for portable devices powered by 1-3 Li-Ion cells, providing a regulated 3.3V or 5V rail. Its wide 2.7V to 15V input range ensures stable output as the battery discharges from 4.2V down to 2.7V. The low shutdown current of 1µA extends standby time, and the 2.5A output can power application processors, displays, and wireless modules. The synchronous architecture achieves up to 95% efficiency, minimizing heat in compact enclosures. Designers should select an inductor with appropriate saturation current and use low-ESR ceramic capacitors for stable operation.
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Industrial Power Supplies
In industrial systems, the LTC3112EFE#PBF can generate a regulated 12V rail from a 12V lead-acid battery that may sag to 9V or rise to 15V during charging. Its buck-boost topology maintains a constant output despite these fluctuations. The 2.5A output can drive sensors, actuators, and communication interfaces. The device's thermal shutdown and current mode control provide robust protection in harsh environments. For best performance, ensure adequate PCB copper area for heat dissipation and place the inductor close to the IC to minimize parasitic inductance.
推薦
RF Transmitters and Power Amplifiers
The LTC3112EFE#PBF provides a clean, low-noise supply for RF power amplifiers and transmitters. Its 4-switch architecture minimizes output voltage ripple, which is critical for maintaining signal integrity. The 2.5A output can support high-power RF modules, and the 1.2MHz switching frequency is above the AM band, reducing interference. The adjustable output allows precise voltage setting for optimal PA efficiency. Use a low-ESR output capacitor and a shielded inductor to further reduce EMI.
推薦
LED Lighting with Current Regulation
The LTC3112EFE#PBF can be configured as a constant-current source for LED lighting, maintaining consistent brightness as the input voltage varies. Its buck-boost capability allows it to drive LEDs from a wide range of sources, such as 12V automotive systems or battery packs. The 2.5A output can power multiple high-brightness LEDs in series. The device's high efficiency reduces heat generation, and its PWM dimming capability (via the SHDN pin) enables precise brightness control. Ensure the inductor is rated for the peak current and use a sense resistor with appropriate power rating.
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Multiple Power Input Systems
The LTC3112EFE#PBF is ideal for systems that can be powered from multiple sources, such as USB, battery, or AC adapter. Its wide input range allows it to accept any of these sources and produce a stable output. The seamless transition between buck and boost modes ensures no glitches when switching sources. The 2.5A output can power the entire system, and the low shutdown current helps preserve battery when external power is present. Designers should implement input OR-ing diodes or a power path controller to manage multiple sources.
推薦
Backup Capacitor Stack
The LTC3112EFE#PBF can efficiently charge and discharge a backup capacitor stack, providing hold-up power during brief power interruptions. Its buck-boost topology allows it to charge the capacitor stack to a voltage higher than the input, and then boost the capacitor voltage to maintain a regulated output as it discharges. The 2.5A output can support critical loads like solid-state drives or industrial controllers. The device's high efficiency maximizes the usable energy stored in the capacitors. Use supercapacitors with appropriate voltage ratings and ensure the charging current is limited.
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推薦產品摘要
工程參考資料，適用於 LTC3112EFE#PBF — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LTC3112EFE#TRPBF | LTC3112IFE#PBF | LTC3112IDHD#TRPBF | LTC3112MPDHD#PBF | LTC3115HFE-1#PBF |
|---|---|---|---|---|---|---|
| Package | 20-TSSOP Exposed Pad | 20-TSSOP Exposed Pad | 20-TSSOP Exposed Pad | DFN-16 | DFN-16 | TSSOP-20 |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Input Voltage Range | 2.7V to 15V | 2.7V to 15V | 2.7V to 15V | 2.7V to 15V | 2.7V to 15V | 2.7V to 40V |
| Output Current | 2.5A | 2.5A | 2.5A | 2.5A | 2.5A | 2A |
| Output Voltage Range | 2.5V to 14V | 2.5V to 14V | 2.5V to 14V | 2.5V to 14V | 2.5V to 14V | 1.8V to 40V |
| Switching Frequency | 1.2MHz | 1.2MHz | 1.2MHz | 1.2MHz | 1.2MHz | 1.2MHz |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | -40°C to +125°C | -40°C to +125°C | -55°C to +150°C | -40°C to +125°C |
| Shutdown Current | 1µA | 1µA | 1µA | 1µA | 1µA | 1µA |
主要差異化特點
- Higher output current than LTC3115HFE-1#PBF (對比LTC3115HFE-1#PBF)
- Wider input voltage range than LTC3112IDHD#TRPBF (對比LTC3112IDHD#TRPBF)
- Lower shutdown current than many competitors (對比LTC3115HFE-1#PBF)
設計說明
For optimal performance, place the input and output capacitors as close as possible to the IC pins. Use a 10µF ceramic capacitor on the input and a 22µF ceramic capacitor on the output. The inductor should be placed near the SW pins to minimize parasitic inductance. Ensure a solid ground plane under the IC and connect the exposed pad to the ground plane with multiple vias for thermal and electrical performance.
The LTC3112EFE#PBF can dissipate significant power at high output currents. The TSSOP-20 package with exposed pad has a thermal resistance of approximately 40°C/W. At 2.5A output and 5V output from 12V input, power dissipation is about 2.5W, leading to a 100°C temperature rise. Use a copper pour of at least 1 square inch on the PCB to keep the junction temperature below 125°C. Consider forced airflow if ambient temperature is high.
Avoid using an inductor with insufficient saturation current rating, as this can cause core saturation and efficiency loss. The inductor should be rated for at least 3A saturation current. Also, ensure the feedback resistor divider uses 1% tolerance resistors to maintain output voltage accuracy. Do not exceed the absolute maximum input voltage of 15V, as this can damage the IC. Use a Schottky diode from SW to GND if the output is shorted to protect the internal switches.
合規資訊
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified. Lead-free finish.
