参数资料
| 型号： | MAX6952EAX+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 18/21页 |
| 文件大小： | 0K |
| 描述： | IC DRVR DSPL LED 36-SSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 1,000 |
| 显示器类型： | LED |
| 配置： | 5 x 7（矩阵） |
| 接口： | 4 线串行 |
| 数字或字符： | 4 位数字 |
| 电流 - 电源： | 12mA |
| 电源电压： | 2.7 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 36-BSOP（0.295"，7.50mm 宽） |
| 供应商设备封装： | 36-SSOP |
| 包装： | 带卷 (TR) |
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5 ? 7 Matrix LED Display Driver
Table 23. Display-Test Register Format
REGISTER DATA
MODE
Normal operation
Display test
ADDRESS
CODE (HEX)
0x07
0x07
D7
X
X
D6
X
X
D5
X
X
D4
X
X
D3
X
X
D2
X
X
D1
X
X
D0
0
1
The voltage drop across the drivers with a nominal 5V
supply (5.0V - 2.4V) = 2.6V is nearly 3 times the drop
across the drivers with a nominal 3.3V supply (3.3V -
2.4V) = 0.9V. In most systems, consumption is an
important design criterion, and the MAX6952 should be
operated from the system ’ s 3.3V nominal supply. In
other designs, the lowest supply voltage may be 5V.
The issue now is to ensure the dissipation limit for the
MAX6952 is not exceeded. This can be achieved by
inserting a series resistor in the supply to the MAX6952,
ensuring that the supply decoupling capacitors are still
on the MAX6952 side of the resistor. For example, con-
sider the requirement that the minimum supply voltage
to a MAX6952 must be 3.0V, and the input supply
range is 5V ±5%.
Maximum supply current is:
12mA + (40mA x 10) = 412mA
Minimum input supply voltage is 4.75V.
Maximum series resistor value is:
(4.75V - 3.0V) / 0.412A = 4.25 ?
We choose 3.3 ? ±5%. Worst-case resistor dissipation
is at maximum toleranced resistance, i.e., (0.412A) 2 x
(3.3 ? ? 1.05) = 0.577W. We choose a 1W resistor rat-
ing. The maximum MAX6952 supply voltage is at maxi-
mum input supply voltage and minimum toleranced
resistance, i.e., 5.25V - (0.412A x 3.3 ? ? 0.95) = 3.97V.
Low-Voltage Operation
The MAX6952 works over the 2.7V to 5.5V supply
range. The minimum useful supply voltage is deter-
mined by the forward voltage drop of the LEDs at the
peak current I SEG , plus the 0.6V headroom required by
the driver output stages. The MAX6952 correctly regu-
lates I SEG with a supply voltage above this minimum
voltage. If the supply drops below this minimum volt-
age, the driver output stages may brown out, and be
unable to regulate the current correctly. As the supply
voltage drops further, the LED segment drive current
becomes effectively limited by the output driver's on-
resistance, and the LED drive current drops. The char-
acteristics of each individual LED in a 5 ? 7 matrix digit
are well matched, so the result is that the display inten-
sity dims uniformly as supply voltage drops out of regu-
lation and beyond. The MAX6952 operates down to
2.5V supply voltage (although most displays are very
dim at this voltage), provided that the MAX6952 is pow-
ered up initially to at least 2.7V to trigger the device's
internal reset.
Computing Power Dissipation
The upper limit for power dissipation (PD) for the
MAX6952 is determined from the following equation:
P D = (V+ ? 12mA) + (V+ - V LED ) (DUTY x I SEG ? N)
where:
V+ = supply voltage
Duty = duty cycle set by intensity register
N = number of segments driven (worst case is 10)
V LED = LED forward voltage
I SEG = segment current set by R SET
P D = power dissipation, in mW if currents are in mA
Dissipation example:
I SEG = 40mA, N = 10, Duty = 15 / 16, V LED =
2.4V at 40mA, V+ = 3.6V
P D = 3.6V (12mA) + (3.6V - 2.4V)(15 / 16 ? 40mA ? 10)
= 0.493W
Thus, for a 36-pin SSOP package (T JA = 1 / 0.0118 =
+85 ° C/W from operating ratings), the maximum allowed
ambient temperature T A is given by:
T J(MAX) = T A + (P D ? T JA ) = +150 ° C =
T A + (0.493 ? +85 ° C/W)
So, T A = +108 ° C. Thus, the part can be operated safely
at a maximum package temperature of +85 ° C.
Power Supplies
The MAX6952 operates from a single 2.7V to 5.5V
power supply. Bypass the power supply to GND with a
0.1μF capacitor as close to the device as possible. Add
a 47μF capacitor if the MAX6952 is not close to the
board ’ s input bulk decoupling capacitor.
18
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX6953EAX+T | IC DRVR DSPL LED 36-SSOP |
| MAX6954AAX | IC DRIVER LED SEG 14/16 36-SSOP |
| MAX6955ATL+T | IC DRVR DSPL LED 40-TQFN |
| MAX6956ATL/V+ | IC DRIVER LED PORT 20/28 40WQFN |
| MAX6957ANI | IC DRIVER LED PORT 20/28 28-DIP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX6952EPL | 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube |
| MAX6952EPL+ | 功能描述:LED显示驱动器 MAX6952EPL+ RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube |
| MAX6952EVKIT | 功能描述:LED 照明开发工具 RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| MAX6953EAX | 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube |
| MAX6953EAX+ | 功能描述:LED显示驱动器 2.7-5.5V 4-Digit 5x7 Matrix LED Driver RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。