LTC3307A

采用 2 mm x 2 mm LQFN 封装的 5 V、3 A 同步降压型 Silent Switcher

英文数据手册

Rev. B

推荐新设计使用

顶部

概览

优势和特点
产品详情

优势和特点

与LTC3308(4A)和LTC3309(6A)引脚兼容
高效率：8mΩ NMOS，31mΩ PMOS
可编程频率：1MHz - 3MHz
- 小型电感和电容
峰值电流模式控制
- 22ns最短导通时间
- 宽带宽、快速瞬态响应
Silent Switcher^® 架构
- 超低EMI辐射

低纹波突发工作模式(Burst Mode^®)，I_Q为40µA
可在过载情况下安全地承受电感饱和
V_IN 范围：2.25V至5.5V
V_OUT 范围：0.5V至 V_IN
V_OUT 精度：±1%(全温度范围)
精准400mV使能阈值，关断时1µA
电源良好指示、内部补偿和软启动
散热增强型2mm x 2mm LQFN封装
通过AEC-Q100汽车应用认证

产品详情

LTC3307A是一款非常小巧、高效率、低噪声、单片同步3A降压型DC/DC转换器，采用2.25V至5.5V输入电源。该稳压器在1MHz至3MHz的开关频率下使用恒定频率峰值电流模式控制，最小导通时间低至22 ns，可通过小型外部元件实现快速瞬态响应。Silent Switcher架构可最大程度地降低EMI辐射。

LTC3307A可在强制连续或脉冲跳跃模式下工作以实现低噪声，或在低纹波突发模式下工作以在轻负载条件时实现高效率，适用于电池供电系统。该IC可将输出电压调节到最低500mV。其他特性包括输出过压保护、短路保护、热关断、时钟同步以及高达100%占空比运行以实现低压差。该器件采用薄型12引脚 2mm×2mm×0.74mm LQFN封装，并带有裸焊盘以降低热阻。

应用

光网络、服务器、电信
汽车、工业、通信
分布式直流电源系统(POL)
FPGA、ASIC、微处理器内核电源
电池供电系统

产品分类

电源管理

产品生命周期推荐新设计使用

本产品已上市。数据手册包含所有最终性能规格和工作条件。ADI公司推荐新设计使用这些产品。

评估套件 (1)

DC2990A

LTC3307A | 5V Input to 1.2V Output at 3A Synchronous Step‑Down Silent Switcher Demo Circuit

DC2990A

查看此评估套件详细信息

Demonstration circuit 2990A features the LTC3307A 5V, 3A synchronous step-down Silent Switcher^® operating as a 2MHz, 3.3V to 1.2V 3A buck regulator. The LTC3307A supports adjustable output voltages from 0.5V to V_IN with operating frequencies from 1MHz up to 3MHz. The LTC3307A is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. A minimum on-time of 22ns enables high V_IN to low V_OUT conversion ratios at high frequencies.

The DC2990A operating mode may be selected as Burst, Skip or forced continuous (FC) mode. Setting JP1 to the FC/SYNC position will allow the LTC3307A to sync to a clock frequency from 1MHz to 3MHz. The LTC3307A operates in forced continuous mode when syncing to an external clock. The DC2990A is set to a fixed 2MHz frequency by connecting RT to V_IN through a 0Ω resistor, R9. The frequency can be easily changed by removing R9 and setting an appropriate resistor in the R4 location to obtain the desired frequency. Refer to the LTC3307A data sheet for the proper RT value for a desired switching frequency.

The DC2990A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the V_IN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3307A data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with this demo manual. The LTC3307A is assembled in a 2mm × 2mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

The Efficiency vs Load graph shows the efficiency and the power loss of the circuit with a 3.3V input in Burst Mode operation.