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参数资料
| 型号： | MAX1716EEG+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 17/33页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 24-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 550kHz |
| 占空比： | 100% |
| 电源电压： | 2 V ~ 28 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 24-SSOP（0.154"，3.90mm 宽） |
| 包装： | 管件 |
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High-Speed, Adjustable, Synchronous Step-Down
Controllers with Integrated Voltage Positioning
? i
? t
=
V BATT - V OUT
L
-I PEAK
-I PEAK
I LOAD
I LOAD = I PEAK /2
I LIMIT
0
ON-TIME
TIME
0
TIME
Figure 3. Pulse-Skipping/Discontinuous Crossover Point
switching frequency. The on-time guaranteed in the
Electrical Characteristics table is influenced by switch-
ing delays in the external high-side MOSFET. Resistive
losses — including the inductor, both MOSFETs, output
capacitor ESR, and PC board copper losses in the out-
Figure 4. “ Valley ” Current-Limit Threshold Point
between continuous and discontinuous inductor-cur-
rent operation. For an input voltage (V+) range of 7V to
24V, this threshold is relatively constant, with only a
minor dependence on the input voltage:
≈ ?
? ? ?
put and ground — tend to raise the switching frequency
at higher output currents. Switch dead-time can
increase the effective on-time, reducing the switching
I LOAD ( SKIP )
? K × V OUT ? ? V + ? V OUT ?
? 2 L ? ? V + ?
frequency. This effect occurs only in PWM mode ( SKIP
= high) when the inductor current reverses at light or
negative load currents. With reversed inductor current,
the inductor ’ s EMF causes LX to go high earlier than
normal, extending the on-time by a period equal to the
DH-rising dead-time.
When the controller operates in continuous mode, the
dead-time is no longer a factor and the actual switching
frequency is:
? = (V OUT + V DROP1 ) / [t ON × (V+ + V DROP1 – V DROP2 )]
where V DROP1 is the sum of the parasitic voltage drops
in the inductor discharge path, including synchronous
rectifier, inductor, and PC board resistances; V DROP2 is
the sum of the resistances in the charging path, includ-
ing high-side switch, inductor, and PC board resis-
tances; and t ON is the on-time calculated by the
MAX1716/MAX1854/MAX1855.
Automatic Pulse-Skipping Switchover
In skip mode ( SKIP = low), an inherent automatic
switchover to PFM takes place at light loads (Figure 3).
This switchover is controlled by a comparator that trun-
cates the low-side switch on-time at the inductor cur-
rent ’ s zero crossing. This mechanism causes the
threshold between pulse-skipping PFM and nonskip-
ping PWM operation to coincide with the boundary
where K is the on-time scale factor (Table 3). The load-
current level at which PFM/PWM crossover occurs,
I LOAD(SKIP) , is equal to 1/2 the peak-to-peak ripple cur-
rent, which is a function of the inductor value (Figure 3).
For example, in the standard application circuit with
K = 3.3μs (300kHz), V BATT = 12V, V OUT = 1.6V, and
L = 0.68μH, switchover to pulse-skipping operation
occurs at I LOAD = 2.3A or about 1/4 full load. The
crossover point occurs at an even lower value if a
swinging (soft-saturation) inductor is used.
The switching waveforms may appear noisy and asyn-
chronous when light loading causes pulse-skipping
operation; this is a normal operating condition that
improves light-load efficiency. Trade-offs in PFM noise
vs. light-load efficiency are made by varying the induc-
tor value. Generally, low inductor values produce a
broader efficiency vs. load curve, while higher values
result in higher full-load efficiency (assuming that the
coil resistance remains fixed) and less output voltage
ripple. Penalties for using higher inductor values
include larger physical size and degraded load-tran-
sient response (especially at low input voltage levels).
Forced-PWM Mode ( S K I P = High)
The low-noise, forced-PWM mode ( SKIP driven high)
disables the zero-crossing comparator that controls the
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相关代理商/技术参数 |
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| MAX1716EEG+ | 功能描述:DC/DC 开关控制器 Adj Synchronous Step-Down RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1716EEG+T | 功能描述:DC/DC 开关控制器 Adj Synchronous Step-Down RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1716EEG-T | 功能描述:DC/DC 开关控制器 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX17175ETG+ | 制造商:Maxim Integrated Products 功能描述:BOOST REG W/INTEGRATED CHARGE PUMPS SWITCH CONTROL & HIGH-CU - Rail/Tube |
| MAX1717BEEG | 功能描述:DC/DC 开关控制器 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
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