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参数资料
| 型号： | MAX16977SATE/V+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 13/18页 |
| 文件大小： | 0K |
| 描述： | IC BUCK SYNC ADJ 2A 16TQFN |
| 标准包装： | 60 |
| 类型： | 降压（降压） |
| 输出类型： | 两者兼有 |
| 输出数： | 1 |
| 输出电压： | 5V，1 V ~ 10 V |
| 输入电压： | 3.5 V ~ 36 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 1MHz ~ 2.2MHz |
| 电流 - 输出： | 2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | * |
| 封装/外壳： | * |
| 包装： | * |
| 供应商设备封装： | * |
MAX16977
36V, 2A, 2.2MHz Step-Down Converter
with Low Operating Current
L = OUT SUP OUT
ratio (LIR = 0.3). The switching frequency, input voltage,
output voltage, and selected LIR then determine the
inductor value as follows:
V (V ? V )
V SUP f SW I OUT LIR
Table 1. Inductor Siz e Comparison
INDUCTOR SIZE
SMALLER LARGER
Lower price Smaller ripple
Smaller form factor Higher efficiency
where V SUP , V OUT , and I OUT are typical values (so that
efficiency is optimum for typical conditions). The switch-
Faster load response
Larger fixed-frequency
range in skip mode
? I INDUCTOR =
ESR IN =
I OUT +
? I L = SUP OUT OUT
? I INDUCTOR
= I LOAD(MAX) +
C IN = OUT
and D =
ing frequency is set by R FOSC (see the Internal Oscillator
section). The exact inductor value is not critical and can
be adjusted to make trade-offs among size, cost, efficien-
cy, and transient response requirements. Table 1 shows
a comparison between small and large inductor sizes.
The inductor value must be chosen so that the maximum
inductor current does not reach the device’s minimum
current limit. The optimum operating point is usually
found between 25% and 35% ripple current. When pulse
skipping (FSYNC low and light loads), the inductor value
also determines the load-current value at which PFM/
PWM switchover occurs.
Find a low-loss inductor having the lowest possible
DC resistance that fits in the allotted dimensions. Most
inductor manufacturers provide inductors in standard
values, such as 1.0 F H, 1.5 F H, 2.2 F H, 3.3 F H, etc. Also
look for nonstandard values, which can provide a bet-
ter compromise in LIR across the input voltage range. If
using a swinging inductor (where the no-load inductance
decreases linearly with increasing current), evaluate
the LIR with properly scaled inductance values. For
the selected inductance value, the actual peak-to-peak
inductor ripple current ( D I INDUCTOR ) is defined by:
V OUT (V SUP ? V OUT )
V SUP × f SW × L
where D I INDUCTOR is in A, L is in H, and f SW is in Hz.
Ferrite cores are often the best choices, although pow-
dered iron is inexpensive and can work well at 200kHz.
The core must be large enough not to saturate at the
peak inductor current (I PEAK ):
2
Input Capacitor
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
ripple on the input caused by the circuit’s switching.
Maxim Integrated
The input capacitor RMS current requirement (I RMS ) is
defined by the following equation:
V OUT (V SUP ? V OUT )
I RMS = I LOAD(MAX)
V SUP
I RMS has a maximum value when the input voltage
equals twice the output voltage (V SUP = 2V OUT ), so
I RMS(MAX) = I LOAD(MAX) /2.
Choose an input capacitor that exhibits less than 10 N C
self-heating temperature rise at the RMS input current for
optimal long-term reliability.
The input-voltage ripple is composed of D V Q (caused
by the capacitor discharge) and D V ESR (caused by the
equivalent series resistance (ESR) of the capacitor). Use
low-ESR ceramic capacitors with high ripple-current
capability at the input. Assume the contribution from the
ESR and capacitor discharge equal to 50%. Calculate
the input capacitance and ESR required for a specified
input-voltage ripple using the following equations:
? V ESR
? I L
2
where
(V ? V ) × V
V SUP × f SW × L
and
I × D(1 ? D) V OUT
? V Q × f SW V SUPSW
where I OUT is the maximum output current, and D is the
duty cycle.
Output Capacitor
The output filter capacitor must have low enough ESR to
meet output ripple and load-transient requirements, yet
have high enough ESR to satisfy stability requirements.
13
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX16977SAUE/V+ | 功能描述:直流/直流开关转换器 36V 2.2MHz Step Down 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 |
| MAX16977SAUE/V+T | 功能描述:直流/直流开关转换器 36V 2A 2.2MHz Step-Down 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 |
| MAX16977SAUE+ | 制造商:Maxim Integrated Products 功能描述:36V, 2A, 2.2MHZ STEP-DOWN CONVERTER WITH LOW OPERATING CURRE - Rail/Tube 制造商:Maxim Integrated Products 功能描述:IC REG BUCK SYNC 5V/ADJ 16TSSOP |
| MAX16977SAUE+T | 制造商:Maxim Integrated Products 功能描述:36V, 2A, 2.2MHZ STEP-DOWN CONVERTER WITH LOW OPERATING CURRE - Tape and Reel |
| MAX1697REUT | 制造商:Maxim Integrated Products 功能描述:- Cut Tape Product |
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