- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383333 > MAX1718EEI (MAXIM INTEGRATED PRODUCTS INC) Notebook CPU Step-Down Controller for Intel Mobile Voltage Positioning IMVP-II PDF資料下載
參數(shù)資料
| 型號： | MAX1718EEI |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Notebook CPU Step-Down Controller for Intel Mobile Voltage Positioning IMVP-II |
| 中文描述： | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO28 |
| 封裝： | 0.150 INCH, 0.025 INCH PITCH, MO-137AD, QSOP-28 |
| 文件頁數(shù)： | 12/35頁 |
| 文件大?。?/td> | 700K |
| 代理商： | MAX1718EEI |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁當(dāng)前第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁
M
Notebook CPU Step-Down Controller for Intel
Mobile Voltage Positioning (IMVP-II)
12
______________________________________________________________________________________
Detailed Description
5V Bias Supply (V
CC
and V
DD
)
The MAX1718 requires an external 5V bias supply in
addition to the battery. Typically, this 5V bias supply is
the notebook’s 95% efficient 5V system supply.
Keeping the bias supply external to the IC improves
efficiency and eliminates the cost associated with the
5V linear regulator that would otherwise be needed to
supply the PWM circuit and gate drivers. If stand-alone
capability is needed, the 5V supply can be generated
with an external linear regulator.
The 5V bias supply must provide V
CC
(PWM controller)
and V
DD
(gate-drive power), so the maximum current
drawn is:
I
BIAS
= I
CC
+ f (Q
G1
+ Q
G2
) = 10mA to 40mA (typ)
where I
CC
is 800μA (typ), f is the switching frequency,
and Q
G1
and Q
G2
are the MOSFET data sheet total
gate-charge specification limits at V
GS
= 5V.
V+ and V
DD
can be tied together if the input power
source is a fixed 4.5V to 5.5V supply. If the 5V bias
supply is powered up prior to the battery supply, the
enable signal (SKP/
SDN
going from low to high or
open) must be delayed until the battery voltage is pre-
sent to ensure startup.
Free-Running, Constant On-Time PWM
Controller with Input Feed-Forward
The Quick-PWM control architecture is a pseudofixed-
frequency, constant-on-time current-mode type with
voltage feed-forward (Figure 2). This architecture relies
on the output filter capacitor’s ESR to act as the cur-
rent-sense resistor, so the output ripple voltage pro-
vides the PWM ramp signal. The control algorithm is
simple: the high-side switch on-time is determined sole-
ly by a one-shot whose period is inversely proportional
to input voltage and directly proportional to output volt-
age. Another one-shot sets a minimum off-time (400ns
typ). The on-time one-shot is triggered if the error com-
parator is low, the low-side switch current is below the
current-limit threshold, and the minimum off-time one-
shot has timed out.
On-Time One-Shot (TON)
The heart of the PWM core is the one-shot that sets the
high-side switch on-time. This fast, low-jitter, adjustable
one-shot includes circuitry that varies the on-time in
response to battery and output voltage. The high-side
switch on-time is inversely proportional to the battery
voltage as measured by the V+ input, and proportional
to the output voltage. This algorithm results in a nearly
constant switching frequency despite the lack of a
fixed-frequency clock generator. The benefits of a con-
stant switching frequency are twofold: first, the frequency
can be selected to avoid noise-sensitive regions such
as the 455kHz IF band; second, the inductor ripple-cur-
rent operating point remains relatively constant, resulting
in easy design methodology and predictable output
voltage ripple.
On-Time = K (V
OUT
+ 0.075V) / V
IN
where K is set by the TON pin-strap connection and
0.075V is an approximation to accommodate the expect-
ed drop across the low-side MOSFET switch (Table 2).
The on-time one-shot has good accuracy at the operating
points specified in the
Electrical Characteristics table
(±10% at 200kHz and 300kHz, ±12% at 550kHz and
1000kHz). On-times at operating points far removed from
the conditions specified in the
Electrical Characteristics
table can vary over a wider range. For example, the
1000kHz setting will typically run about 10% slower with
inputs much greater than +5V due to the very short on-
times required.
On-times translate only roughly to switching frequencies.
The on-times guaranteed in the
Electrical Character-
istics
table are influenced by switching delays in the
Table 1. Component Suppliers
MANUFACTURER
Central Semiconductor
Dale-Vishay
Fairchild
International Rectifier
Kemet
Motorola
Nihon
Panasonic
Taiyo Yuden
TDK
Toko
Sanyo
SGS-Thomson
Sumida
Zetex
USA PHONE
516-435-1110
402-564-3131
408-721-2181
310-322-3331
408-986-0424
602-303-5454
847-843-7500
714-373-7939
408-573-4150
847-390-4373
800-745-8656
619-661-6835
617-259-0300
708-956-0666
516-543-7100
FACTORY FAX
516-435-1824
402-563-6418
408-721-1635
310-322-3332
408-986-1442
602-994-6430
847-843-2798
714-373-7183
408-573-4159
847-390-4428
408-943-9790
619-661-1055
617-259-9442
708-956-0702
516-864-7630
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX1718 | Replaced by TMS320VC5506 : Digital Signal Processors 100-LQFP -40 to 85 |
| MAX1718BEEI | Notebook CPU Step-Down Controller for Intel Mobile Voltage Positioning IMVP-II |
| MAX1720EUTG | Switched Capacitor Voltage Inverter with Shutdown |
| MAX1724EZK50 | 1.5uA IQ, Step-Up DC-DC Converters in Thin SOT23-5 |
| MAX1724EZK30 | 1.5uA IQ, Step-Up DC-DC Converters in Thin SOT23-5 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX1718EEI+ | 制造商:Maxim Integrated Products 功能描述:LDO CNTRLR STDN 0.6V TO 1.75V 28QSOP - Rail/Tube |
| MAX1718EEI+T | 制造商:Maxim Integrated Products 功能描述:LDO CNTRLR STDN 0.6V TO 1.75V 28QSOP - Tape and Reel |
| MAX1718EEI-C71059 | 制造商:Maxim Integrated Products 功能描述:NOTEBOOK CPU STEP-DOWN CONTROLLER FOR INTEL M - Rail/Tube |
| MAX1718EEI-T | 制造商:Maxim Integrated Products 功能描述:NOTEBOOK CPU STEP-DOWN CONTROLLER FOR INTEL M - Tape and Reel |
| MAX1718EEI-TG068 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。