MIC3202YME - Electronic component Microchip - Free user manual and instructions
Find the device manual for free MIC3202YME Microchip in PDF.
User questions about MIC3202YME Microchip
0 question about this device. Answer the ones you know or ask your own.
Ask a new question about this device
Download the instructions for your Electronic component in PDF format for free! Find your manual MIC3202YME - Microchip and take your electronic device back in hand. On this page are published all the documents necessary for the use of your device. MIC3202YME by Microchip.
USER MANUAL MIC3202YME Microchip
The MIC3202/MIC3202-1 is a hysteretic step-down, constant-current, High-Brightness LED (HB LED) driver. It provides an ideal solution for interior/exterior lighting, architectural and ambient lighting, LED bulbs, and other general illumination applications.
This board enables the evaluation of the MIC3202/MIC3202-1 for 1A LED current. The board is optimized for ease of testing, with all the components on a single side. The device operates from a 6V to 37V input voltage range, and includes an integrated 1.0A MOSFET. When the input voltage approaches and crosses UVLO threshold, the internal 5V V_CC is regulated and the integrated MOSFET is turned on if EN pin and DIM pin are high. The inductor current builds up linearly. When the CS pin voltage hits the V_CS(MAX) with respect to V_IN , the internal MOSFET is turned off and the Schottky diode takes over and returns the current to V_IN . Then the current through inductor and LEDs starts decreasing. When CS pin hits V_CS(MIN) , the internal MOSFET is turned on and the cycle repeats.
Since the control scheme does not need loop compensation, it makes for a very simple design and avoids problems of instability.
Datasheets and support documentation can be found on Micrel's web site at: www.micrel.com.
Requirements
This board needs a single-bench power source adjustable over the input voltage of 6V < V_IN < 37V that can provide at least 1A of current. The loads can either be active (electronic load in CV mode) or passive (LEDs) with the ability to dissipate the maximum load power while keeping accessible surfaces ideally <70^ .
Precautions
There is no reverse input protection on this board. When connecting the input sources, ensure that the correct polarity is observed.
In the line transient condition, such as hot plug-in, an electrolytic capacitor may be required at the VIN and GND terminals in order to prevent IC damage from a surge voltage.
Getting Started
- Connect V_IN supply to the input VIN and GND terminals. With the output of this supply disabled, set the supply voltage to the desired input test voltage (6V < V_IN < 37V). This supply voltage should be monitored at the test boards input terminals to allow voltage drops in the test cables (and ammeter if used) to be accounted for. An ammeter can be added inline with the +VIN input terminal to accurately measure input current.
- Connect the LEDs to the output terminals between LED+ and LED-. This LED voltage drop depends on manufacturer tolerance and number of LEDs. The LED current can be measured using an ammeter or current probe. A 4.7μF ceramic capacitor helps to reduce the current ripple through the LED. The LED current is set to 1A by a 200mΩ current-sense resistor (R _CS ).
- Enable the input supply. By default, the IC is enabled when the input voltage crosses the VIN threshold (4V) and the internal VCC regulator and internal MOSFET are turned on with the EN and DIM pins are high. To use the EN and DIM functions of the MIC3202/MIC3202-1, a test point is provided for each of them.
Ordering Information
Part Number Description
MIC3202YME EV MIC3202YME Evaluation Board
Other Features
EN Input
The EN pin provides a logic level control of the output and the voltage has to be 2.0V or higher to enable the current regulator. The output stage is gated by the DIM pin. When the EN pin is pulled low, the regulator goes to off-state and the supply current of the device is reduced to below 1 A. Do not drive the EN pin above the supply voltage.
DIM Input
The DIM pin provides a logic level control for brightness of the LED. A PWM input can be used to control the brightness of LED. DIM high enables the output and its voltage has to be 2.0V or higher. DIM low disables the output, regardless of EN high-state.
Current-Sense Input
The CS pin provides the high-side current sense to set the LED current with an external sense resistor.
A sense resistor R_CS is placed between V_IN and LED+ terminals.
The current through LED is sensed by the sense resistor ( R_CS ). The sensed voltage is fed back to the MIC3202 to regulate the LED current
R_cs is given by:
$$ R _ {C S} = \frac {1}{2} x (\frac {V + V}{I _ {L E D}}) ^ {\text { MIN(CS)MAX(CS)}} \text { Error! } $$
Bookmark not defined.
I_LED is LED current required to set.
| R_CS (Ω) | I_LED (A) I | ^2R (W) Size (SMD) | |
| 1.33 | 0.15 | 0.03 | 0603 |
| 0.56 | 0.35 | 0.07 | 0805 |
| 0.4 | 0.5 | 0.1 | 0805 |
| 0.28 | 0.7 | 0.137 | 0805 |
| 0.2 | 1.0 | 0.2 | 1206 |
For V_CS(MAX) and V_CS(MIN) refers to the Electrical Characteristics table.
Frequency of Operation
To calculate the frequency spread across input supply:
$$ F _ {\mathrm{SW}} = \frac {(V _ {\mathrm{D}} + I _ {\mathrm{LED}} \times R _ {\mathrm{CS}} + V _ {\mathrm{LED}}) \times (V _ {\mathrm{IN}} - I _ {\mathrm{LED}} \times R _ {\mathrm{CS}} - V _ {\mathrm{LED}})}{L \times \Delta I _ {\mathrm{L}} \times (V _ {\mathrm{D}} + V _ {\mathrm{IN}})} $$
$$ \Delta I _ {L} = \frac {V _ {\mathrm{CS(MAX)}} - V _ {\mathrm{CS(MIN)}}}{R _ {\mathrm{CS}}} $$
where:
V_D is Schottky diode forward drop
V_LED is total LEDs voltage drop
V_IN is input voltage
I_LED is average LED current
According to the above equation, choose the inductor to make the operating frequency no higher than 1MHz.
Refer to the datasheet Application Information for more information on components selection guidelines.
Frequency Dithering
The MIC3202 is designed to modulate the V_CS(MAX) with amplitude ±6mV by a pseudo random generator to generate the ±12% of the switching frequency dithering. This spreads the frequency spectrum over a wider range and reduce the EMI noise peaks.
The MIC3202-1 is non-dithering version of the MIC3202.
Evaluation Board Performance
line
| INPUT VOLTAGE (V) | 2LED | 4LED | 8LED | | ---------------- | ----- | ----- | ----- | | 6 | 91.5 | 95.5 | 96.0 | | 14 | 90.0 | 94.5 | 95.5 | | 22 | 88.5 | 93.5 | 94.5 | | 30 | 87.0 | 92.5 | 93.5 | | 38 | 85.5 | 91.5 | 92.5 |
line
| INPUT VOLTAGE (V) | LED CURRENT (%) | | ---------------- | -------------- | | 6 | 0.0% | | 14 | -0.5% | | 22 | -0.8% | | 30 | -0.2% | | 38 | 1.5% |
line
| Time (1μs/div) | V_LX (10V/div) | I_LED (0.5A/div) | | -------------- | -------------- | ----------------- | | 0 | High | Low | | 1 | High | Low | | 2 | High | Low | | 3 | High | Low | | 4 | High | Low | | 5 | High | Low | | 6 | High | Low | | 7 | High | Low | | 8 | High | Low | | 9 | High | Low | | 10 | High | Low | | 11 | High | Low | | 12 | High | Low | | 13 | High | Low | | 14 | High | Low | | 15 | High | Low | | 16 | High | Low | | 17 | High | Low | | 18 | High | Low | | 19 | High | Low | | 20 | High | Low | | 21 | High | Low | | 22 | High | Low | | 23 | High | Low | | 24 | High | Low | | 25 | High | Low | | 26 | High | Low | | 27 | High | Low | | 28 | High | Low | | 29 | High | Low | | 30 | High | Low | | 31 | High | Low | | 32 | High | Low | | 33 | High | Low | | 34 | High | Low | | 35 | High | Low | | 36 | High | Low | | 37 | High | Low | | 38 | High | Low | | 39 | High | Low | | 40 | High | Low | | 41 | High | Low | | 42 | High | Low | | 43 | High | Low | | 44 | High | Low | | 45 | High | Low | | 46 | High | Low | | 47 | High | Low | | 48 | High | Low | | 49 | High | Low | | 50 | High | Low | | 51 | High | Low | | 52 | High | Low | | 53 | High | Low | | 54 | High | Low | | 55 | High | Low | | 56 | High | Low | | 57 | High | Low | | 58 | High | Low | | 59 | High | Low | | 60 | High | Low | | 61 | High | Low | | 62 | High | Low | | 63 | High | Low | | 64 | High | Low | | 65 | High | Low | | 66 | High | Low | | 67 | High | Low | | 68 | High | Low | | 69 | High | Low | | 70 | High | Low | | 71 | High | Low | | 72 | High | Low | | 73 | High | Low | | 74 | High | Low | | 75 | High | Low | | 76 | High | Low | | 77 | High | Low | | 78 | High | Low | | 79 | High | Low | | 80 | High | Low | | 81 | High | Low | | 82 | High | Low | | 83 | High | Low | | 84 | High | Low | | 85 | High | Low | | 86 | High | Low | | 87 | High | Low | | 88 | High | Low | | 89 | High | Low | | 90 | High | Low | | 91 | High | Low | | 92 | High | Low | | 93 | High | Low | | 94 | High | Low | | 95 | High | Low | | 96 | High | Low | | 97 | High | Low | | 98 | High | Low | | 99 | High | Low | | 100 | High | Low | V_IN = 37V V_LED = 1LED I_LED = 1A
line
| Signal | Value | |--------|--------------| | DIM | High | | V_LX | Low | | I_LED | Low |Evaluation Board Schematic
text_image
LED- LED+ C2 4.7μF R1 0.2 L1 47μH R4 2.2 C4 270pF VSW R9 49.9 R5 10 D1 2A/60V VIN 6V TO 37V C3 1.0μF U1 MIC3202 VCC 1 VCC LX 8 EP 7 PGND 6 VIN DIM C7 270pF C1 4.7μF C8 4.7μF C9 1.0μF AGND EN 5 EN R2 100k R3 100k D3 200mA 30V RV1 100k 200mA 30V D2 100k 200mA 30V U2 MIC1557 T/T OUT 5 R7 0 C5 0.1μF GND 3 CS VS 4 R6 10k VCC R8 0 C6 0.1μFNotes:
-
If bulk capacitor on input rail is away (4 inches or more) from the MIC3202/MIC3202-1, install the 100μF bulk capacitor near V_IN .
-
Source impedance should be as low as 10mΩ.
Bill of Materials
| Item | Part Number | Manufacturer Description Qty. | |
| C1, C2, C8 | 12105C475KAZ2A | AVX^(1) | 4.7μF/50V, Ceramic Capacitor, X7R, Size 1210 2 |
| GRM32ER71H475KA88L | Murata^(2) | ||
| C3, C9 | 08053D105KAT2A | AVX^(1) 1μF/25V , Ceramic Capacitor, X5R, Size 0805 1 | |
| GRM21BR71E105KA99L | Murata^(2) | 1μF/25V, Ceramic Capacitor, X7R, Size 0805 1 | |
| C2012X7R1E105K | TDK^(3) | ||
| C4, C7 | 06035C271KAT2A | AVX^(1) | 270pF/50V, Ceramic Capacitor NPO, Size 0603 2 |
| GRM188R71H271KA01D | Murata^(2) | ||
| C5, C6 | 06035C104MAT | AVX^(1) | 0.1μF/50V, Ceramic Capacitor, X7R, Size 0603 2 |
| GRM188R71H104KA93D | Murata^(2) | ||
| C1608X7R1H104K | TDK^(3) | ||
| D1 | SS24-TP | MCC^(4) | 60V, 2A, SMA, Schottky Diode 1 |
| SS24 | Fairchild^(5) | ||
| D2, D3 B0530 | WS-TP MCC | ^(4) 30V, | 200mA, Schottky diode, SOD-323 2 |
| L1 | SLF10145T-470M1R4 | TDK^(3) 47μH, 1.4A, SMT, Power Inductor | 1 |
| R1 | CSR 1/2 0.2 1% I | Stackpole Electronics, Inc ^(7) | 0.2Ω Resistor, 1/2W, 1%, Size 1206 |
| R2, R3 CRCW | W06031003FKEA Vishay ^(8) | 100kΩ Resistor, 1%, Size 0603 | 2 |
| R4 | CRCW08052R20FKEA | Vishay^(8) | 2.2Ω Resistor, 1%, Size 0805 |
| R5 | CRCW080510R0FKEA | Vishay^(8) | 10Ω Resistor, 1%, Size 0805 |
| R6 | CRCW060310K0FKEA | Vishay^(8) | 10kΩ Resistor, 1%, Size 0603 |
| R7, R8 CRCW | W06030000FKEA Vishay ^(8) | 0Ω Resistor, 1%, Size 0603 | 2 |
| R9 | CRCW060349R9FKEA | Vishay^(8) | 49.9Ω Resistor, 1%, Size 0603 |
| RV1 | 3386P-1-104TLF | Bourns^(9) | POT 100kΩ 3/8" SQ CERM SL ST |
| U1 | MIC3202YME | Micrel, Inc.^(10) | High Brightness LED Driver with High-Side Current Sense |
| U2 | MIC1557YM5 | Micrel, Inc.^(10) | RC Time/Oscillator (SOT-23-5) |
Notes:
1. AVX: www.avx.com.
2. Murata: www.murata.com.
3. TDK: www.tdk.com.
4. MCC: www.mccsemi.com.
5. Fairchild: www.fairchildsemi.com.
6. Diodes Inc.: www.diodes.com.
7. Stackpole Electronics: www.seielect.com.
8. Vishay: www.vishay.com.
9. Bourns Inc : www.bourns.com .
10. Micrel, Inc.: www.micrel.com.
PCB Layout Recommendations
text_image
ICREL,Inc MIC3202YME 1955.006 (mil) LED- LED+ VIN GND L1 R9 S1 C4 D1 C2 R1 C8 VIN C3 C9 U1 C7 C8 C1 RV1 EN DIMTop Assembly
text_image
1955.006 (mil) MIC3202YME L1 SW R9 E 1835 (mil) LED- LED+ LED+ VIN GND R7 U2 EN DIM R4 C4 D1 R1 C8 VIN C3 C1 C4 C3 C2 R5 U1 RV1 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15 B16 B17 B18 B19 B20 B21 B22 B23 B24 B25 B26 B27 B28 B29 B30 B31 B32 B33 B34 B35 B36 B37 B38 B39 B40 B41 B42 B43 B44 B45 B46 B47 B48 B49 B50Top Layer
PCB Layout Recommendations (Continued)
text_image
ICREL,Inc 408-944-0800 MIC3202YME +UI Pb Other Pb Rs Rs 1aser.000 (lm) 18830 18830 ECP-000H0-DTBottom Layer
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellect property rights is granted by this document. Except as provided in Micrel's terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property rights
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale.
© 2010 Micrel, Incorporated.