參數(shù)資料
型號(hào)： MAX1938EEI
廠商： MAXIM INTEGRATED PRODUCTS INC
元件分類： 穩(wěn)壓器
英文描述： Two-Phase Desktop CPU Core Supply Controllers with Controlled VID Change
中文描述： SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO28
封裝： 0.150 INCH, 0.025 INCH PITCH, MO-137, QSOP-28
文件頁(yè)數(shù)： 12/24頁(yè)
文件大?。?/td> 586K
代理商： MAX1938EEI
M
Two-Phase Desktop CPU Core Supply Controllers
with Controlled VID Change
12
______________________________________________________________________________________
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:
(
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.
t
K V
V
V
ON
OUT
DROP
VCC
=
+
)
Pin Description (continued)
PIN
NAME
FUNCTION
22
VLG
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.
23
DL1
24
CS1
25
LX1
26
DH1
27
BST1
28
V
CC
相關(guān)PDF資料
PDF描述
MAX1939 Two-Phase Desktop CPU Core Supply Controllers with Controlled VID Change
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX1938EEI-T 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體: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:電源管理IC開發(fā)工具 RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V
MAX1939EEI 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
MAX1939EEI-T 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
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