ON Semiconductor NCV887300LEDGEVB User Manual
NCV887300LEDGEVB
NCV887300 Automotive
Grade High‐frequency
Dimmable LED Boost
Controller Evaluation
Board User's Manual
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EVAL BOARD USER’S MANUAL
Description
This NCV887300 evaluation board provides a convenient
way to evaluate a high-frequency LED Boost converter
design. No additional components are required, other than
dc supplies for the input and enable voltages. An external
clock can be used to synchronize the switching frequency. It
is configured as a 60 mA output current source with a 1 MHz
switching frequency over the typical 6 V to 18 V automotive
input voltage range. On board overvoltage protection is
provided. The design is 1000:1 dimming ratio capable. The
dimming frequency interface circuit may be configured to
accept an 1.8 V or a 3.3 V/5 V control signal.
Key Features
60 mA Output Current Source
1000:1 Dimming Ratio
Overvoltage Protection
1 MHz Switching Frequency
Input Undervoltage Lockout
Internal Soft-Start
Wide Input Voltage of 6 V to 18 V
Regulates through Load Dump Conditions
External Clock Synchronization up to 1.1 MHz
Automotive Grade
Semiconductor Components Industries, LLC, 2013
May, 2013 − Rev. 2
Figure 1. NCV887300 LED Evaluation Board
1 Publication Order Number:
EVBUM2181/D
NCV887300LEDGEVB
Table 1. EVALUATION BOARD TERMINALS
Terminal Function
VIN Positive DC Input Voltage
GND Common DC Return
VOUT Regulated DC Output Voltage
EN/SYNC Enable and Synchronization Input
Table 2. ABSOLUTE MAXIMUM RATINGS (Voltages are with respect to GND)
Rating
DC Supply Voltage (VIN) −0.3 to 40 V
DC Supply Voltage (EN, SYNC) −0.3 to 6 V
Junction Temperature (NCV8902) −40 to 150 C
Ambient Temperature (Evaluation Board) −40 to 105 C
Value Unit
Table 3. ELECTRICAL CHARACTERISTICS (T
Characteristics
REGULATION
Load Current (Adjustable via R3)
SWITCHING
Switching Frequency
Soft-start Time − 1.66 ms
SYNC Frequency Range − 1.0−1.1 MHz
CURRENT LIMIT
Average Current Limit (Load)
Cycle-by-cycle Current Limit (FET) − 0.95 A
PROTECTIONS
Input Undervoltage Lockout (UVLO)
Thermal Shutdown TA Increasing 170 C
=25C, 6 V VIN V
A
Conditions Typical Value Unit
R3 = 3.32 W
− 1000 kHz
− 0.06 A
VIN Decreasing 3.05 V
, VEN= 2 V, unless otherwise specified)
out_LED
60 mA
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Operational Guidelines
1. Connect a DC input voltage, within the 6 V to
40 V range, between VIN and GND.
2. Connect a DC enable voltage, within the 2.0 V to
5.0 V range, between EN/SYNC and GND.
3. Connect a function generator between PWM and
GND. It is recommended the waveform be set to:
125−200 Hz Square Typical Frequency Range
Low State Voltage of 0–0.8 V
High State of 1.8−5 V Range
Duty Cycle from 0.1% to 100%
4. Overvoltage may be tested by enabling the board
(EN/SYNC) with jumper J1 removed.
+
V
in
−
NCV887300LEDGEVB
5. Optionally:
for external clock synchronization, connect a
pulse source between EN/SYNC and GND. The
high state level should be within the 1.8 to 5 V
range
to 0.8 V range, with a minimum pulse width of
40 ns and a frequency within the 1 MHz and
1.1 MHz range.
Jumper J1 should be removed if an external load
is to be used instead of on-board LEDs. Input
voltage operating range is valid for loads
requiring V
*
, and the low state level within the −0.3 V
<40V.
out
Optional Load
(Must Remove J1)
PWM
Dimming
Figure 2. Evaluation Board Connections
*The dimming frequency interface circuit may be configured to accept either an 1.8 V or a 3.3 V/5 V control signal (refer to schematic). For a
1.8 V signal, use BOM and schematic as is. For a 3.3 V/5 V control signal, components R8, R9, R10, R11, Q6 are optional (R14 = 3.01K if
mentioned components are removed).
V
enable
+
−
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