参数资料
型号: MAX1556ETB/V+T
厂商: Maxim Integrated Products
文件页数: 8/12页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 1.2A 10TDFN
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)
输出类型: 可调式
输出数: 1
输出电压: 0.75 V ~ 5.5 V
输入电压: 2.6 V ~ 5.5 V
PWM 型: 电流模式
频率 - 开关: 1MHz
电流 - 输出: 1.2A
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: 10-WFDFN 裸露焊盘
包装: 带卷 (TR)
供应商设备封装: 10-TDFN-EP(3x3)
16μA I Q , 1.2A PWM DC-DC
Step-Down Converters
As the load current decreases, the converters enter a
pulse-skip mode in which the PWM comparator is dis-
abled. At light loads, efficency is enhanced by a
pulse-skip mode in which switching occurs only as
1.0
0.5
needed to service the load. Quiescent current in skip
mode is typically 16μA. See the Light-Load Switching
Waveforms and Load Transient graphs in the Typical
Operating Characteristics.
Load-Transient Response/
Voltage Positioning
The MAX1556/MAX1556A/MAX1557 match the load
regulation to the voltage droop seen during transients.
0
-0.5
-1.0
-1.5
-2.0
V IN = 3.6V
V IN = 2.6V
V IN = 5.5V
This is sometimes called voltage positioning. The load
line used to achieve this behavior is shown in Figures 4
-2.5
0
200
400
600
800
1000
1200
and 5. There is minimal overshoot when the load is
removed and minimal voltage drop during a transition
from light load to full load. Additionally, the MAX1556,
MAX1556A, and MAX1557 use a wide-bandwidth feed-
back loop to respond more quickly to a load transient
than regulators using conventional integrating feedback
loops (see Load Transient in the Typical Operating
Characteristics).
LOAD CURRENT (mA)
Figure 4. MAX1556 Voltage-Positioning Load Line
1.0
0.8
0.6
The MAX1556/MAX1556A/MAX1557 use of a wide-band
control loop and voltage positioning allows superior
load-transient response by minimizing the amplitude
and duration of overshoot and undershoot in response
to load transients. Other DC-DC converters, with high
gain-control loops, use external compensation to main-
tain tight DC load regulation but still allow large voltage
droops of 5% or greater for several hundreds of
microseconds during transients. For example, if the
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
V IN = 3.6V
V IN = 2.6V
V IN = 5.5V
load is a CPU running at 600MHz, then a dip lasting
0
200
400
600
100μs corresponds to 60,000 CPU clock cycles.
Voltage positioning on the MAX1556/MAX1556A/
MAX1557 allows up to 2.25% (typ) of load-regulation
voltage shift but has no further transient droop. Thus,
during load transients, the voltage delivered to the CPU
remains within spec more effectively than with other
regulators that might have tighter initial DC accuracy. In
summary, a 2.25% load regulation with no transient
droop is much better than a converter with 0.5% load
regulation and 5% or more of voltage droop during load
transients. Load-transient variation can be seen only
with an oscilloscope (see the Typical Operating
Characteristics), while DC load regulation read by a
voltmeter does not show how the power supply reacts
to load transients.
Dropout/100% Duty-Cycle Operation
The MAX1556/MAX1556A/MAX1557 function with a low
input-to-output voltage difference by operating at 100%
duty cycle. In this state, the high-side p-channel
LOAD CURRENT (mA)
Figure 5. MAX1557 Voltage-Positioning Load Line
MOSFET is always on. This is particularly useful in
battery-powered applications with a 3.3V output. The sys-
tem and load might operate normally down to 3V or less.
The MAX1556/MAX1556A/MAX1557 allow the output to
follow the input battery voltage as it drops below the regu-
lation voltage. The quiescent current in this state rises
minimally to only 27μA (typ), which aids in extending bat-
tery life. This dropout/100% duty-cycle operation achieves
long battery life by taking full advantage of the entire bat-
tery range.
The input voltage required to maintain regulation is a
function of the output voltage and the load. The differ-
ence between this minimum input voltage and the out-
put voltage is called the dropout voltage. The dropout
voltage is therefore a function of the on-resistance of
the internal p-channel MOSFET (R DS(ON)P ) and the
inductor resistance (DCR).
8
_______________________________________________________________________________________
相关PDF资料
PDF描述
MAX1565ETJ+ IC DGTL CAM PWR-SUP 5CH 32TQFN
MAX1567ETL+ IC DGTL CAM PWR-SUP 6CH 40TQFN
MAX1572ETC180+ IC REG BUCK SYNC 1.8V .8A 12TQFN
MAX1579ETG+ IC PS BIAS/WHITE LED TFT 24-TQFN
MAX1584ETJ+ IC DGTL CAM PWR-SUP 5CH 32TQFN
相关代理商/技术参数
参数描述
MAX1556EVKIT 功能描述:电源管理IC开发工具 MAX1556 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MAX1557ETB 制造商:Maxim Integrated Products 功能描述:16MICROAMP QUIESCENT CURRENT 1.2A - Rail/Tube
MAX1557ETB+ 制造商:Maxim Integrated Products 功能描述:CONV DC-DC SGL-OUT STEP DOWN 10TDFN EP - Rail/Tube
MAX1557ETB+T 功能描述:直流/直流开关转换器 16uA IQ 1.2A PWM Step-Down 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
MAX1557ETB-T 功能描述:直流/直流开关转换器 16uA IQ 1.2A PWM Step-Down 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