SP7616EB [SIPEX]
Evaluation Board Manual; 评估板手册
| 型号： | SP7616EB |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | Evaluation Board Manual |
| 文件： | 总4页 (文件大小：67K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SP7616
Evaluation Board Manual
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
LED Drivers for parallel connected LED
Ultra Low Dropout Voltage of 150mV
No EMI, no switching noise
Integrated current matching
PWM and Analog brightness control
Enable/Shutdown control
Shutdown current < 1µA
SP7616 Eval Board Top Side (not to scale)
DESCRIPTION AND BOARD SCHEMATIC
This Evaluation Board is designed to help the user evaluate performance of the SP7616 for use
as a LED Driver. The evaluation board is a completely assembled and tested surface mount
board which provides easy probe access points to all inputs and outputs so that the user can
quickly connect and measure electrical characteristics and waveforms. The Evaluation Board
schematic diagram is shown in Figure 1. The SP7616 driver provides a simple solution for a
matched current source for any color LED. The current in the LEDs is programmed by an
external resistor. The SP7616 is capable of driving up to four LED chains from a source of up to
30Vin.
The evaluation board contains one SP7616 driver, and four locations to solder the led chains for
ease of use. The user will need to supply an active high PWM signal or an external power
supply with at least 2.5V volts to turn the Sp7616 driver on. (Note R2 on the PCB is referred to
as Rset in the data sheet.)
R2=46K
Figure 1. Evaluation Board Schematic Diagram for SP7616
Rev 07/28/06
SP7616 Evaluation Board Manual
Copyright 2006 Sipex Corporation
USING THE EVALUATION BOARD
1) Vin requirements and PWM pin
The user of the SP7616 will need to supply Vin and an PWM signal that is active high. The
PWM pin signal is a logic level signal and should range between 0 an 5V. The threshold is 2.4V
for a logic high.
2) Setting the LED current
The LED current is set through the Iset resistor. The SP7616 provides an internal reference
voltage that is set to 1V at the ISETPin (Pin3). RSET is then determined by using equation 1.
R2 = VISET*IMULT/ILED (kΩ),
(1)
Where
VISET is the internal reference (1V)
IMULT Current Multiplication Ratio
ILED is the desired Led current.
In example 1: For a 20mA LED current, the current set resistor should be
R2=1V*920/20mA (kΩ),
R2=46K
3) LED dimming
PWM dimming
The LED dimming control is done through the PWM pin. The acceptable frequency range of this
signal is 100Hz to 5 kHz. The acceptable duty cycle range of the signal is 10% to 90% at 1KHZ.
When the PWM pin is driven low, only the LED current sources are disabled while the rest of the
chip is still enabled. .
Analog dimming control
Besides digital PWM control, the LED current can be controlled continuously (from high to low
LED current) by raising the voltage at the bottom of RSET from 0V to 1V maximum. RSET value
may be determined from equation 1. Equation 2 shows the effect of using a VMOD in the circuit
on the Led current
ILED = (1V – VMOD)*IMULT/RSET mA
(2)
Where
1V typical ISET pin voltage
IMULT Current Multiplication Ratio
ILED is the desired Led current.
VMOD is the adjustment voltage
VMOD is an adjustment voltage applied to the bottom side of R2, 920 is a typical current
multiplication ratio IMULT, and ILED is a required LED current in mA/channel. Figure 2 shows the
location of the external VMOD source.
2
R2=46K
Figure 2
4) EVALUATION BOARD LAYOUT
Figure 4. SP7616 Evaluation Board Layout top side (not an actual size)
Bottom Side PCB
Figure 5. SP7616 Evaluation Board Layout bottom side (not an actual size)
Table 2. SP761X_EB List of Materials
Reference
Designator
U1
Comments
Count
Value Part Number
SP7616
Manufacturer
SP7616
1
1
1
C1
1uF
GRM21BR71H105KA12L Murata
Vishay
1uF 50V capacitor 805 size
R2 (RSET) 46K
GND VIN
PWM
CRCW06034602J
Post for Vin PWM signal and
GND
3
K24C/M
Vector Electronic
3
ORDERING INFORMATION
Temperature Range
Model
Package Type
SP7616_EB......................... -40°C to +85°C.................................................................. SP7616 Evaluation Board
4
相关型号：
©2020 ICPDF网 联系我们和版权申明