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参数资料
| 型号： | MAX1997ETJ+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 29/31页 |
| 文件大小： | 0K |
| 描述： | IC PWR SUPPLY TFT LCD 32TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 控制器，TFT LCD |
| 输入电压： | 2.7 V ~ 5.5 V |
| 输出数： | 5 |
| 输出电压： | 2.7 V ~ 13 V |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-WFQFN 裸露焊盘 |
| 供应商设备封装： | 32-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
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Quintuple/Triple-Output TFT LCD Power Supplies
with Fault Protection and VCOM Buffer
the width of the power ground traces improves effi-
V N
V P
ciency and reduces output voltage ripple and noise
spikes. All the other ground connections, such as
the IN pin bypass capacitor and the linear-regulator
output capacitors, should be star-connected to the
backside of the device with wide traces. Make no
other connections between these separate ground
V IN
3.3V TO 5V
GATE
IN
LX
FB
V MAIN
+9V
planes.
3) Place the IN pin and REF pin bypass capacitors as
close to the device as possible.
4) Place all feedback voltage-divider resistors as
OCN
OCP
SWITCH
CONTROL
STEP-UP
REGULATOR
close to their respective feedback pins as possible.
The divider ’ s center trace should be kept short.
Placing the resistors far away causes their FB
OCN
PGND
traces to become antennas that can pick up switch-
ing noise. Care should be taken to avoid running
REF
REF
MAX1997
MAX1998
any feedback trace parallel to its associated drive
trace or near LX or the switching nodes in the
charge pumps.
GND
Figure 14. Disabling Input MOSFET Switch
Applications Information
PC Board Layout and Grounding
Careful PC board layout is extremely important for
proper operation. Use the following guidelines for good
PC board layout:
1) The high-current loops of the main step-up regula-
tors are shown in Figure 12. Minimize the area of
these loops by placing the input bypass capacitors,
output diode, and output capacitors less than 0.2in
(5mm) from the LX and PGND pins. Connect these
components with traces as wide as possible. Avoid
using vias in the high-current paths. If vias are
unavoidable, use many vias in parallel to reduce
resistance and inductance.
2) Create islands for the analog ground (GND), power
ground (PGND), and linear-regulator ground.
Connect all three ground areas (islands) at only one
location, which is the backside pad of the device.
The REF bypass capacitor and all feedback dividers
should be connected to the analog ground island
(GND). The step-up regulator ’ s input and output
capacitors, and the charge-pump components
should be a wide power ground plane. The power
ground plane should be connected to the power
ground pin (PGND) with a wide trace. Maximizing
5) Minimize the length and maximize the width of the
traces between the output capacitors and the load
for best transient responses.
6) Minimize the size of the LX node while keeping it
wide and short. Keep the LX node away from feed-
back nodes (FB, FBP, and FBN) and analog
ground. Use DC traces as a shield, if necessary.
Large ground planes on a multilayer board can pro-
vide additional shielding.
Refer to the MAX1997 evaluation kit for an example of
proper board layout.
Additional Application Circuits
Operation with Main Output Voltage >13V
The maximum output voltage of the step-up regulator is
13V, which is limited by the absolute maximum rating of
the internal power MOSFET. To achieve higher output
voltage, an external N-channel MOSFET can be cas-
coded with the internal FET (Figure 13). Since the gate
of the external FET is biased from the input supply, use
a logic-level FET to ensure that the FET is fully
enhanced at the minimum input voltage. The current
rating of the FET needs to be higher than the internal
current limit.
Disabling Input MOSFET Switch
If the input protection MOSFET is not needed, disable
the input overcurrent comparator by connecting the
OCP pin to ground, and the OCN pin to REF. Leave the
GATE pin floating (Figure 14).
______________________________________________________________________________________
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1997EVKIT | 制造商:Maxim Integrated Products 功能描述:QUINTUPLE/TRIPLE OUTPUT TFT LCD POWER SUPPLIE - Bulk |
| MAX19983A | 功能描述:上下转换器 RoHS:否 制造商:Texas Instruments 产品:Down Converters 射频:52 MHz to 78 MHz 中频:300 MHz LO频率: 功率增益: P1dB: 工作电源电压:1.8 V, 3.3 V 工作电源电流:120 mA 最大功率耗散:1 W 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PQFP-128 |
| MAX19985AETX+ | 功能描述:上下转换器 High-Gain 700MHz to 1GHz Downconv RoHS:否 制造商:Texas Instruments 产品:Down Converters 射频:52 MHz to 78 MHz 中频:300 MHz LO频率: 功率增益: P1dB: 工作电源电压:1.8 V, 3.3 V 工作电源电流:120 mA 最大功率耗散:1 W 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PQFP-128 |
| MAX19985AETX+T | 功能描述:上下转换器 High-Gain 700MHz to 1GHz Downconv RoHS:否 制造商:Texas Instruments 产品:Down Converters 射频:52 MHz to 78 MHz 中频:300 MHz LO频率: 功率增益: P1dB: 工作电源电压:1.8 V, 3.3 V 工作电源电流:120 mA 最大功率耗散:1 W 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PQFP-128 |
| MAX19985ETX+ | 功能描述:上下转换器 Dual, SiGe, .7-1GHz Downconversion Mixer RoHS:否 制造商:Texas Instruments 产品:Down Converters 射频:52 MHz to 78 MHz 中频:300 MHz LO频率: 功率增益: P1dB: 工作电源电压:1.8 V, 3.3 V 工作电源电流:120 mA 最大功率耗散:1 W 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PQFP-128 |
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