参数资料
型号: MAX1623EAP
厂商: Maxim Integrated Products
文件页数: 7/12页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 3A 20SSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 66
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 1.1 V ~ 3.8 V
输入电压: 4.5 V ~ 5.5 V
PWM 型: 电流模式,混合
频率 - 开关: 最高 350kHz
电流 - 输出: 3A
同步整流器:
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 20-SSOP(0.209",5.30mm 宽)
包装: 管件
供应商设备封装: 20-SSOP
3A, Low-Voltage, Step-Down Regulator with
Synchronous Rectification and Internal Switches
V IN
4.5V TO
5.5V
FBSEL
IN
FB
FEEDBACK
SELECTION
COMP
CURRENT
REF
G m
SENSE
SKIP
V IN
V CC
REF
PWM LOGIC
AND
DRIVERS
LX
MAX1623
SHDN
REF
REF
GND
TIMER
TOFF
CURRENT
SENSE
PGND
NOTE: HEAVY LINES DENOTE HIGH SWITCHING CURRENT PATHS.
Figure 1. Functional Diagram
Idle Mode
At light loads, the device goes into skip mode
(because the load current is below the skip threshold),
and Idle Mode operation (1.25A current limit) begins.
This allows both switches to remain off at the end of the
off-time, skipping cycles to reduce switching losses. At
lighter loads, the inductor current is discontinuous
because the inductor current reaches zero. In Idle
Mode, the operating frequency varies with output load
current. There is no major shift in circuit behavior as the
PWM limit falls below the skip limit. The effective off-
time simply increases, resulting in a seamless transition
between PWM mode and Idle Mode.
PWM Mode
PWM operation occurs whenever the load current is
greater than the skip threshold. In this mode, the PWM
comparator adjusts the current limit to the desired out-
put current, so that the P-channel turns on at the end of
each off-time.
Three signals are resistively summed at the input of the
PWM comparator (Figure 1): an output voltage error
signal relative to the reference voltage, an integrated
output voltage error correction signal, and the sensed
PMOS switch current. The integrated error signal is
provided by a transconductance amplifier with an
external capacitor at the COMP pin. This integrator pro-
vides high DC accuracy without the need for a high-
gain error amplifier. Connecting a capacitor at COMP
modifies the overall loop response (see the Integrator
Comparator section).
Setting the Output Voltage
There are two preset output voltages (2.525V and
3.33V), or the output voltage can be adjusted from the
reference voltage (nominally 1.1V) up to 3.8V. For a
preset output voltage (Figure 2), connect FB to the out-
put voltage, and connect FBSEL to V CC (2.525V out-
put) or leave it unconnected (3.33V output). For an
adjustable output, connect FBSEL to GND or REF, and
connect FB to the midpoint of a resistor divider
between the output voltage and ground (Figure 3).
Regulation is maintained when V FB equals V REF . Select
R1 in the 10k ? to 500k ? range. R2 is given by:
R2 = (R1)(V OUT /V REF ? 1)
where V REF is typically 1.1V.
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7
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相关代理商/技术参数
参数描述
MAX1623EA-P 制造商:Maxim Integrated Products 功能描述:
MAX1623EAP+ 功能描述:直流/直流开关调节器 3A Step-Down w/Synch Rectification RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX1623EAP+T 功能描述:直流/直流开关调节器 3A Step-Down w/Synch Rectification RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX1623EAP-T 功能描述:直流/直流开关调节器 RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX1623EVKIT 功能描述:直流/直流开关调节器 Evaluation Kit for the MAX1623 RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5