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| 型号： | MAX1937EEI+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 12/24页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR PWM HYBRID 28-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| PWM 型： | 混合物 |
| 输出数： | 1 |
| 频率 - 最大： | 500kHz |
| 占空比： | 50% |
| 电源电压： | 6 V ~ 24 V |
| 降压： | 无 |
| 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： | 0°C ~ 85°C |
| 封装/外壳： | 28-QSOP |
| 包装： | 带卷 (TR) |
Two-Phase Desktop CPU Core Supply
Controllers with Controlled VID Change
Pin Description (continued)
PIN
22
23
24
25
26
27
28
NAME
VLG
DL1
CS1
LX1
DH1
BST1
V CC
FUNCTION
DL_ Driver Power-Supply Input. Connect to a 4.5V to 6.5V supply for powering the low-side MOSFET
gate drive, and the bootstrap circuit for driving the high-side MOSFETs. Ensure that V VLG is greater
than or equal to V VDD .
Low-Side MOSFET Gate-Driver Output. Connect to the low-side MOSFET gate. DL1 is pulled low in
shutdown.
Negative Current-Sense Input. Connect to a current-sense resistor in series with the low-side
MOSFET or connect to LX1 to use the low-side MOSFET’s on-resistance for current sensing.
Inductor Connection. Connect to the switched side of the inductor.
High-Side MOSFET Gate-Drive Output. Connect to the high-side MOSFET gate. DH1 is pulled low in
shutdown.
High-Side MOSFET Gate-Driver Bootstrap Input. Connect 0.22μF or higher value bypass capacitor
from BST1 to LX1. Keep trace length as short as possible. Connect a Schottky diode between BST1
and VLG. See the Selecting a BST Capacitor section.
Input Voltage Sense. Connect to the input supply at the high-side MOSFET drain. The voltage
sensed at V CC is used to set the on-time.
( )
Detailed Description
The MAX1937/MAX1938/MAX1939 is a family of syn-
chronous, two-phase step-down controllers capable of
delivering load currents up to 60A. The controllers use
Quick-PWM control architecture in conjunction with
active load current voltage positioning. Quick-PWM
control provides instantaneous load-step response,
while programmable voltage positioning allows the con-
verter to utilize full transient regulation limits, reducing
the output capacitance requirement. Furthermore, the
two phases operate 180° out-of-phase with an effective
500kHz switching frequency, thus reducing input and
output current ripple, as well as reducing input filter
capacitor requirements.
The MAX1937/MAX1938/MAX1939 are compliant with
the AMD Hammer, Intel VRM 9.0/VRM 9.1, and AMD
Athlon Mobile VID code specifications (see Table 1 for
VID codes). The internal DAC provides ultra-high accu-
racy of ±0.75%. A controlled VID voltage transition is
implemented to minimize both undervoltage and over-
voltage overshoot during VID input change.
Remote sensing is available for high output-voltage
accuracy. The MOSFET switches are driven by with a
6V gate-drive circuit to minimize switching and
crossover conduction losses to achieve efficiency as
high as 90%. The MAX1937/MAX1938/ MAX1939 fea-
ture cycle-by-cycle current limit to ensure current limit
is not exceeded. Crowbar protection is available to pro-
tect against output overvoltage.
On-Time One-Shot
The heart of the Quick-PWM core is the one-shot that
sets the high-side switch on-time. This fast, low-jitter,
one-shot circuitry varies the on-time in response to the
input and output voltages. The high-side switch on-time
is inversely proportional to the voltage applied to V CC
and directly proportional to the output voltage. This
algorithm results in a nearly constant switching fre-
quency, despite the lack of a fixed-frequency clock
generator. The benefits of a constant switching fre-
quency are twofold: the frequency selected avoids
noise-sensitive regions, and the inductor ripple current
operating point remains relatively constant, resulting in
easy design methodology and predictable output volt-
age ripple:
K V OUT + V DROP
t ON =
V VCC
where the constant K is 4μs and V DROP is the voltage
drop across the low-side MOSFET’s on-resistance plus
the drop across the current-sense resistor (V DROP ≈
75mV), if used.
The on-time one-shot has good accuracy at the operat-
ing point specified in the Electrical Characteristics . On-
times at operating points far removed from the
conditions specified in the Electrical Characteristics can
vary over a wide range. For example, the regulators run
slower with input voltages greater than 12V because of
the very short on-times required.
12
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1937EEI-TG069 | 制造商:Maxim Integrated Products 功能描述: |
| MAX1938EEI | 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 |
| MAX1938EEI-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 |
| MAX1938EEI-TG069 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1938EVKIT | 功能描述:电源管理IC开发工具 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 |
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