参数资料
型号: MAX15037ATE+
厂商: Maxim Integrated Products
文件页数: 12/25页
文件大小: 0K
描述: IC REG BUCK BST SYNC ADJ 16TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 60
类型: 降压(降压),升压(升压)
输出类型: 可调式
输出数: 1
输出电压: 0.6 V ~ 23 V
输入电压: 4.5 V ~ 23 V
PWM 型: 电压模式
频率 - 开关: 312kHz ~ 2.1MHz
电流 - 输出: 3A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 16-WQFN 裸露焊盘
包装: 管件
供应商设备封装: 16-TQFN-EP(5x5)
2.2MHz, 3A Buck or Boost Converters
with an Integrated High-Side Switch
Enable
EN is an active-high input that turns the MAX15036/
MAX15037 on and off. EN is a TTL-logic input with 2.0V
and 0.8V logic-high and low levels, respectively. When
EN is asserted high, the internal digital soft-start cycle
slowly ramps up the internal reference and provides
some soft-start at the output. Hysteresis provides immu-
nity to the glitches during logic turn-on of the converter.
Large voltage variations at EN can interrupt the soft-start
sequence and can cause a latch-up. Ensure that EN
remains high for at least 5ms once it is asserted. Force
EN low to turn off the internal power MOSFET and cause
RESET to go low (MAX15036) or cause PGOOD to go
low (MAX15037). Connect EN to V L when not used.
Soft-Start/Soft-Stop
The MAX15036/MAX15037 include UVLO with hystere-
sis to prevent chattering during startup. The UVLO cir-
cuit holds the MAX15036/MAX15037 off until V+
reaches 4.5V and turns the devices off when V+ falls
below 4.3V. The MAX15036/MAX15037 also offer a
soft-start feature that reduces surge currents and
glitches on the input during turn-on. During turn-on
when the UVLO threshold is reached or EN goes from
low to high, the digital soft-start ramps up the reference
(V BYPASS ) in 64 steps. During a turn-off (by driving EN
or V+ low), the reference is reduced to zero slowly. The
soft-start and soft-stop periods (t SS ) are 4096 cycles of
the internal oscillator. To calculate the soft-start/soft-stop
period use the following equation:
the turn-on edge of the internal n-channel power MOSFET
with a fixed propagation delay. When operating the
MAX15036/MAX15037 with an external SYNC clock,
R OSC must be installed. Program the internal switching
frequency so that (0.8 x f SYNC ) ≤ f SW ≤ (1.2 x f SYNC ). The
minimum pulse width for f SYNC is 100ns. Connect SYNC
to SGND if synchronization is not used.
The CKO output (MAX15036 only) is a logic-level clock
with the same frequency as f SW and with 115° phase
shift with respect to SYNC clock. Two MAX15036s can
be connected in a master/slave configuration for two-
phase (180°) interleaved operation. The CKO output of
the master drives the SYNC input of the slave to form a
dual-phase converter. To achieve the 180° out-of-phase
operation, program the internal switching frequency of
both converters close to each other by using the same
R OSC value. When synchronizing the master-slave con-
figuration using external clock, program the internal
switching frequency using R OSC close to the external
clock frequency (f SYNC ) for 180° ripple phase operation
(see Figure 8). Any difference in the internal switching
frequency and f SYNC changes the phase delay. If both
master and slave converters use the same power
source, and share input bypass capacitors, the effec-
tive switching frequency at the input is twice the switch-
ing frequency of the individual converter. Higher ripple
frequency at the input capacitor means a lower RMS
ripple current into the capacitor.
Current Limit
t SS =
4096
f SW
The MAX15036/MAX15037 protect against output over-
load and short-circuit conditions when operated in a
buck configuration. An internal current-sensing stage
develops a voltage proportional to the instantaneous
f SW is the switching frequency of the converter.
Oscillator/Synchronization
(SYNC)/Clock Output (CLKOUT)
The clock frequency (or switching frequency) is gener-
ated internally and is adjustable through an external
resistor connected from OSC to SGND. The relationship
between R OSC and f SW is:
switch current. When the switch current reaches 4.6A
(typ), the power MOSFET turns off and remains off until
the next on cycle.
During a severe overload or short-circuit condition when
the output voltage is pulled to ground, the discharging
slope of the inductor is V DS (the voltage across the syn-
chronous FET), or V F (the voltage across the rectifying
diode) divided by L. The short off-time does not allow
R OSC =
125 × 10 8 Ω / s
f SW
the current to properly ramp down in the inductor, caus-
ing a dangerous current runaway and possibly destruc-
tion of the device. To prevent this, the MAX15036/
The adjustment range for f SW is from 200kHz to
2.2MHz.
Connect a logic-level clock between 200kHz to 2.2MHz
at SYNC to externally synchronize the MAX15036/
MAX15037’s oscillator (see Figure 8). The MAX15036/
MAX15037 synchronize to the rising edge of the SYNC
clock. The rising edge of the SYNC clock corresponds to
MAX15037 include a frequency foldback feature. When
the current limit is detected the frequency is reduced to
1/4th of the programmed switching frequency. When the
output voltage falls below 1/3rd of its nominal set point
(V FB = 0.2V), the converter is turned off and soft-start
cycle is initiated. This reduces the RMS current sourced
by the converter during the fault condition.
12
______________________________________________________________________________________
相关PDF资料
PDF描述
MAX15038ETG+T IC REG BUCK SYNC ADJ 4A 24TQFN
MAX15039ETG+T IC REG BUCK SYNC ADJ 6A 24TQFN
MAX15041ETE+T IC REG BUCK SYNC ADJ 3A 16TQFN
MAX15046AAEE+T IC REG CTRLR BUCK PWM VM 16-QSOP
MAX15049ETJ+ IC CTRLR PWM STP-DN TRIPL 32WQFN
相关代理商/技术参数
参数描述
MAX15037ATE/V+ 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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
MAX15037ATE/V+T 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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
MAX15037ATE+ 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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
MAX15037ATE+T 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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
MAX15038ETG+ 功能描述:直流/直流开关调节器 4A 2MHz Step-Down w/Integrated Switch 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