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参数资料
| 型号： | MAX5073ATI+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 11/25页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK BST ADJ 1A/2A 28TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 降压（降压），升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 2 |
| 输出电压： | 0.8 V ~ 28 V |
| 输入电压： | 4.5 V ~ 23 V |
| PWM 型： | 电压模式 |
| 频率 - 开关： | 200kHz ~ 2.2MHz |
| 电流 - 输出： | 1A，2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
2.2MHz, Dual-Output Buck or Boost Converter
with Internal Power MOSFETs
Internal Oscillator/Out-of-Phase Operation
The internal oscillator generates the 180° out-of-phase
clock signal required by each regulator. The internal
oscillator frequency is programmable from 400kHz to
4.4MHz using a single 1% resistor at R OSC . Use the fol-
lowing equation to calculate R OSC :
input of the slave. The effective input ripple switching
frequency shall be four times the individual converter’s
switching frequency. When driving the master convert-
er using external clock at SYNC, set the clock duty
cycle to 50% for a 90° phase-shifted operation.
Input Voltage (V+)/Internal Linear
R OSC =
25 × 10
f OSC
9
Regulator (VL)
All internal control circuitry operates from an internally
regulated nominal voltage of 5.2V (VL). At higher input
where f OSC is the internal oscillator frequency in hertz
and R OSC in ohms.
The two independent regulators in the MAX5073 switch
180° out-of-phase to reduce input filtering require-
ments, to reduce electromagnetic interference (EMI),
and to improve efficiency. This effectively lowers com-
ponent cost and saves board space, making the
MAX5073 ideal for cost-sensitive applications.
With dual synchronized out-of-phase operation, the
MAX5073’s high-side MOSFETs turn on 180° out-of-
phase. The instantaneous input current peaks of both
regulators do not overlap, resulting in reduced RMS rip-
ple current and input voltage ripple. This reduces the
required input capacitor ripple current rating, allows for
fewer or less expensive capacitors, and reduces
shielding requirements for EMI. The out-of-phase wave-
forms in the Typical Operating Characteristics demon-
strate synchronized 180° out-of-phase operation.
Synchronization (SYNC)/
Clock Output (CLKOUT)
The main oscillator can be synchronized to the system
clock by applying an external clock (f SYNC ) at SYNC.
The f SYNC frequency must be twice the required oper-
ating frequency of an individual converter. Use a TTL
logic signal for the external clock with at least a 100ns
pulse width. R OSC is still required when using external
synchronization. Program the internal oscillator fre-
quency so 0.2f SYNC < f OSC < 1.2f SYNC . The rising
edge of f SYNC synchronizes the turn-on edge of the
internal MOSFET (see Figure 3).
voltages (V+) of 5.5V to 23V, VL is regulated to 5.2V.
At 5.5V or below, the internal linear regulator operates
in dropout mode, where VL follows V+. Depending on
the load on VL, the dropout voltage can be high
enough to reduce VL below the undervoltage lockout
(UVLO) threshold.
For input voltages of less than 5.5V, connect V+ and VL
together. The load on VL is proportional to the switch-
ing frequency of converter 1 and converter 2. See the
Dropout Voltage vs. Switching Frequency graph in the
Typical Operating Characteristics . For input voltage
ranges higher than 5.5V, use the internal regulator.
Bypass V+ to SGND with a low-ESR, 0.1μF or greater
ceramic capacitor placed close to the MAX5073. Current
spikes from VL may disturb internal circuitry powered by
VL. Bypass VL with a low-ESR, ceramic 0.1μF capacitor
to PGND and 4.7μF capacitor to SGND.
Undervoltage Lockout/Soft-Start
The MAX5073 includes an undervoltage lockout with
hysteresis and a power-on-reset circuit for converter
turn-on and monotonic rise of the output voltage. The
rising UVLO threshold is internally set to 4.3V with a
175mV hysteresis. Hysteresis at UVLO eliminates “chat-
tering” during startup. When VL drops below UVLO, the
internal switches are turned off.
Digital soft-start is provided internally to reduce input
surge currents and glitches at the input during turn-on.
When UVLO is cleared and EN_ is high, digital soft-
start slowly ramps up the internal reference voltage in
64 steps. The total soft-start period is 2048 switching
cycles of the internal oscillator.
R OSC =
25 × 10 9
f OSC
To calculate the soft-start period, use the following
equation:
where f OSC is the internal oscillator frequency in hertz
and R OSC in ohms, f OSC = 2 x f SW .
Two MAX5073s can be connected in the master-slave
t SS =
2048
f OSC
configuration for four ripple-phase operation. The
MAX5073 provides a clock output (CLKOUT) that is 45°
phase-shifted with respect to the internal switch turn-on
edge. Feed the CLKOUT of the master to the SYNC
where f OSC is the internal oscillator frequency in hertz,
which is twice the switching frequency of each converter.
______________________________________________________________________________________
11
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5073ETI | 功能描述:直流/直流开关转换器 2.2MHz Buck or Boost Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX5073ETI+ | 功能描述:直流/直流开关转换器 2.2MHz Buck or Boost Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX5073ETI+T | 功能描述:直流/直流开关转换器 2.2MHz Buck or Boost Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX5073ETI-T | 功能描述:直流/直流开关转换器 2.2MHz Buck or Boost Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX5073ETJ | 制造商:Maxim Integrated Products 功能描述:- Rail/Tube |
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