LTC3240-3.3/LTC3240-2.5 是升压/降压型充电泵 DC/DC 转换器，可在很宽的输入电压范围内 (1.8V 至 5.5V) 产生一个固定的已调输出电压 (3.3V 或 2.5V)。

当输入电压高于已调输出电压时，LTC3240 起一个低压差稳压器的作用。一旦输入电压降至比已调输出电压高出的幅度不到 100mV 时，该器件将自动切换至升压模式。在升压模式中，LTC3240 起一个恒定频率 (1.2MHz) 倍压充电泵的作用。

LTC3240-3.3/LTC3240-2.5 具有很低的无负载工作电流 (典型值为 65μA)，并在停机模式中具有超低的工作电流 (< 1μA)。内置软起动电路可防止在启动期间产生过大的涌入电流。热停机和电流限制电路使得该器件能够承受 VOUT 至 GND 的连续短路。

LTC3240-3.3/LTC3240-2.5 仅需 3 个纤巧的外部陶瓷电容器，以实现超小的应用占板面积。LTC3240-3.3/LTC3240-2.5 采用 6 引脚 (2mm x 2mm) DFN 封装。
应用

• 两节 AA 电池至 2.5V
• 2 - 3 节 AA 电池/锂离子电池至 3.3V
• 面向众多手持式产品中的照相机、I/O 电源、音频、PC 卡、各种逻辑电路等的低功率电源

• 升压/降压型充电泵产生了固定的 3.3V 或 2.5V 输出
• VIN 范围：1.8V 至 5.5V
• 输出电流高达 150mA
• 自动模式切换
• 在升压模式中执行恒定频率 (1.2MHz) 操作
• 在降压模式中执行低压差稳压器操作
• 低无负载静态电流：IQ = 65μA
• 内置软起动功能可减小涌入电流
• 停机功能可使负载与输入断接
• 停机电流 < 1μA
• 短路/热保护
• 采用 6 引脚 (2mm x 2mm) DFN 封装

LTC3240EDC-2.5#TRMPBF，封装：6-Lead DFN (2mm x 2mm w/ EP)，包装形式及数量：卷带，500，工作温度：-40 to 125C，AD官网报价：2.13（100-499个）；1.82（1000+个）

LTC3240EDC-2.5#TRPBF，封装：6-Lead DFN (2mm x 2mm w/ EP)，包装形式及数量：卷带，2500，工作温度：-40 to 125C，AD官网报价：2.13（100-499个）；1.82（1000+个）

LTC3240EDC-3.3#TRMPBF，封装：6-Lead DFN (2mm x 2mm w/ EP)，包装形式及数量：卷带，500，工作温度：-40 to 125C，AD官网报价：2.13（100-499个）；1.82（1000+个）

LTC3240EDC-3.3#TRPBF，封装：6-Lead DFN (2mm x 2mm w/ EP)，包装形式及数量：卷带，2500，工作温度：-40 to 125C，AD官网报价：2.13（100-499个）；1.82（1000+个）

DC903A-A：LTC3240EDC-3.3 Demo Board | Regulated Buck-Boost Charge Pump, 1.8V ≤ VIN ≤ 5.5V, VOUT = 3.3V @ Up to 150mA

Demonstration circuit 903 is a step-up/step-down charge pump dc-dc converter. It comes with two assembly versions, DC903A-A and DC903A-B featuring the 150mA output current LTC3240-3.3 (3.3V output) and LTC3240-2.5 (2.5V output) respectively, each in a tiny 2mm x 2mm DFN package. The DC903A-A and DC903A-B operate with an input voltage from 1.8V to 5.5V.

When using the DC903A-A, the output current can reach up to 150mA when the input voltage is above 2.5V. The maximum output current of the DC903A-B is 60mA with a 1.8V input voltage. The DC903A optimizes the output efficiency by operating in the LDO step-down mode during the time the input is higher than the output voltage. When the input voltage drops low enough, The LTC3240 automatically switches to charge-pump doubling mode to extend system run-time. Built-in soft-start limits inrush current at turn-on, and short-circuit current limit/thermal protection help the part survive a continuous short-circuit.

Additionally, the DC903A features Automatic Burst Mode operation at light load to achieve low supply current (65µA, no load).

---

DC903A-B：LTC3240EDC-2.5 Demo Board | Regulated Buck-Boost Charge Pump, 1.8V ≤ VIN ≤ 5.5V, VOUT = 2.5V @ Up to 150mA

Demonstration circuit 903 is a step-up/step-down charge pump dc-dc converter. It comes with two assembly versions, DC903A-A and DC903A-B featuring the 150mA output current LTC3240-3.3 (3.3V output) and LTC3240-2.5 (2.5V output) respectively, each in a tiny 2mm x 2mm DFN package. The DC903A-A and DC903A-B operate with an input voltage from 1.8V to 5.5V.

When using the DC903A-A, the output current can reach up to 150mA when the input voltage is above 2.5V. The maximum output current of the DC903A-B is 60mA with a 1.8V input voltage. The DC903A optimizes the output efficiency by operating in the LDO step-down mode during the time the input is higher than the output voltage. When the input voltage drops low enough, The LTC3240 automatically switches to charge-pump doubling mode to extend system run-time. Built-in soft-start limits inrush current at turn-on, and short-circuit current limit/thermal protection help the part survive a continuous short-circuit.

Additionally, the DC903A features Automatic Burst Mode operation at light load to achieve low supply current (65µA, no load).