- 您现在的位置：买卖IC网 > PDF目录383338 > MAX1855EEG (MAXIM INTEGRATED PRODUCTS INC) Replaced by TMS320C6202B : Fixed-Point Digital Signal Processor 352-FCBGA PDF资料下载
参数资料
| 型号： | MAX1855EEG |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | Replaced by TMS320C6202B : Fixed-Point Digital Signal Processor 352-FCBGA |
| 中文描述： | SWITCHING CONTROLLER, 550 kHz SWITCHING FREQ-MAX, PDSO24 |
| 封装： | 0.150 INCH, 0.025 INCH PITCH, QSOP-24 |
| 文件页数： | 14/33页 |
| 文件大小： | 840K |
| 代理商： | MAX1855EEG |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页当前第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页
M
High-Speed, Adjustable, Synchronous Step-Down
Controllers with Integrated Voltage Positioning
14
______________________________________________________________________________________
_______________Detailed Description
The MAX1716/MAX1854/MAX1855 buck controllers are
targeted for low-voltage, high-current CPU core power
supplies for notebook computers that typically require
18A (or greater) load steps. The proprietary Quick-
PWM pulse-width modulator in the converter is specifi-
cally designed for handling fast load steps while
maintaining a relatively constant operating frequency
and inductor operating point over a wide range of input
voltages. The Quick-PWM architecture circumvents the
poor load-transient timing problems of fixed-frequency
current-mode PWMs while also avoiding the problems
caused by widely varying switching frequencies in con-
ventional constant on-time and constant off-time PFM
schemes.
+5V Bias Supply (V
CC
and V
DD
)
The MAX1716/MAX1854/MAX1855 require 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 associat-
ed 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 powers V
CC
(PWM controller) and
V
DD
(gate-drive power). The maximum current is:
I
BIAS
= I
CC
+
×
(Q
G1
+ Q
G2
) = 10mA to 40mA (typ)
where I
CC
is 700μA (typ),
is the switching frequency,
and Q
G1
and Q
G2
are the MOSFET data sheet total
gate-charge specification limits at V
GS
= 5V.
The battery input (V+) and +5V bias inputs (V
CC
and
V
DD
) can be connected together if the input 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 sig-
nal (
SHDN
) must be delayed until the battery voltage is
present to ensure startup.
Free-Running, Constant-On-Time PWM
Controller with Input Feed-Forward
The Quick-PWM control architecture is a constant-on-
time, current-mode type with voltage feed-forward
(Figure 2). This architecture relies on the output ripple
voltage to provide the PWM ramp signal. Thus, the out-
put filter capacitor
’
s ESR acts as a feedback resistor.
The control algorithm is simple: the high-side switch on-
time is determined solely by a one-shot whose period is
inversely proportional to input voltage and directly pro-
portional to output voltage (see
On-Time One-Shot
).
Another one-shot sets a minimum off-time (400ns typ).
The on-time one-shot is triggered if the error compara-
MANUFACTURER
MOSFETs
Fairchild Semiconductor
International Rectifier
Siliconix
CAPACITORS
Kemet
Panasonic
PHONE (COUNTRY CODE)
WEBSITE
(1) 888-522-5372
(1) 310-322-3331
(1) 203-268-6261
www.fairchildsemi.com
www.irf.com
www.vishay.com
(1) 408-986-0424
(1) 847-468-5624
www.kemet.com
www.panasonic.com
Sanyo
(65) 281-3226 (Singapore)
(1) 408-749-9714
www.secc.co.jp
Taiyo Yuden
(03) 3667-3408 (Japan)
(1) 408-573-4150
www.t-yuden.com
TDK
INDUCTORS
Coilcraft
Coiltronics
Sumida
(1) 847-390-4373
www.tdk.com
(1) 800-322-2645
(1) 561-752-5000
(1) 408-982-9660
www.coilcraft.com
www.coiltronics.com
www.sumida.com
Sumitomo
(1) 408-451-8441 (USA)
81 75 961-3141 (Japan)
www.ssmc.co.jp
Table 2. Component Suppliers
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1854 | High-Speed, Adjustable, Synchronous Step-Down Controllers with Integrated Voltage Positioning |
| MAX1857EUA47 | 500mA, Low-Dropout, Ripple-Rejecting LDO in MAX |
| MAX1857 | Replaced by TMS320C6202B : Fixed-Point Digital Signal Processor 352-FCBGA |
| MAX1858 | Dual 180∑ Out-of-Phase Buck Controllers with Sequencing/Prebias Startup and POR |
| MAX1858EEG | Dual 180∑ Out-of-Phase PWM Step-Down Controller with Power Sequencing and POR |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1855EEG+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1855EEG-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 |
| MAX1855EVKIT | 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1716 MAX1854 MAX1855 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 |
| MAX1856EUB | 功能描述:电信线路管理 IC RoHS:否 制造商:STMicroelectronics 产品:PHY 接口类型:UART 电源电压-最大:18 V 电源电压-最小:8 V 电源电流:30 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:VFQFPN-48 封装:Tray |
| MAX1856EUB+ | 功能描述:电信线路管理 IC Synchronizable PWM SLIC Power Supply RoHS:否 制造商:STMicroelectronics 产品:PHY 接口类型:UART 电源电压-最大:18 V 电源电压-最小:8 V 电源电流:30 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:VFQFPN-48 封装:Tray |
发布紧急采购，3分钟左右您将得到回复。