Specifications typical @ +25°C, nominal input voltage & rated output current, unless otherwise noted. Specifications subject to change without notice.
Key Features:
Input
Parameter
•
Constant Current Output
Input Voltage Range
•
Wide 7V to 30V Input Range
Max Input Voltage
Input Filter
•
Efficiency to 95%
Output
•
Miniature MiniDIP Case
Parameter
•
150 mA to 1A Output
Output Voltage Range
Output Current
•
Meets EN 60950
Output Current Accuracy
•
1.6 MHrs MTBF
Output Power
•
Digital & Analog Dimming!
Efficiency
Capacitive Load
Operating Frequency
Ripple & Noise (20 MHz)
Models Available
Temperature Coefficient
with Wire Leads
Thermal Impedance
(IP67 Rated)
Output Short Circuit
Environmental
Parameter
Operating Temperature Range
Storage Temperature Range
Cooling
Humidity
Lead Temperature (Solder)
Remote On/Off Control
Parameter
DC/DC On
DC/DC Off
Remote Pin Drive Current
Quiescent Input Current
(Shutdown Mode)
PWM Dimming
Parameter
Operation Frequency
Switch On Time
Switch Off Time
Output Current Adjustment
Analog Dimming
Parameter
Input Voltage Range
Output Current Adjustment
Control Voltage Range Limits
Drive Current
EMC Compliance
EMI/RFI
Electrostatic Discharge (ESD)
RF Field Susceptibility
Electrical Fast Transients/Bursts On Mains
EMS Immunity
Reliability Specifications
Parameter
MTBF
Conditions
Min.
7.0
Typ.
24
0.5 Sec. Max
Internal Capacitor
Conditions
Min.
Typ.
2
V
IN
= 30V
See Model Selection Guide
See Model Selection Guide
See Model Selection Guide
See Model Selection Guide
Max.
30.0
40.0
Units
VDC
VDC
Max.
28
Units
VDC
40
See Model Selection Guide
±0.03 ±0.08
Natural Convection
+50
Regulated At Rated Output Current
Conditions
Ambient
Case
Min.
-40
Typ.
+25
Max.
+85
+105
+125
95
260
47
380
µF
kHz
%/
º
C
º
C/W
Units
º
C
º
C
-40
Free Air Convection
RH, Non-condensing
1.5 mm From Case For 10 Sec
Conditions
Min.
%
ºC
V
ADJ
= 1.25V
V
IN
= 30V
Conditions
Recommended Maximum
Min.
200
200
0.0
Conditions
At V
ADJ
Input
On
Off
V
ADJ
= 1.25V
Radiated/Conducted
Class A
Class A
Class A
Min.
0.0
25
0.30
0.0
Typ.
Max.
Units
Open or 0.3V < V
ADJ
<1.25V
V
ADJ
<0.15V
1
mA
25
µA
Typ.
Max.
1.0
Units
kHz
nS
nS
%
Units
VDC
%
VDC
mA
100
Typ.
Max.
1.25
100
1.25
0.15
1.0
MicroPower Direct
292 Page Street
Suite D
Stoughton, MA 02072
USA
T:
(781) 344-8226
F:
(781) 344-8481
E:
sales@micropowerdirect.com
W:
www.micropowerdirect.com
EN 55015 (CISPR22)
IEC/EN 61000-4-2, -6, -8
IEC/EN 61000-4-3
IEC/EN 61000-4-4
EN61547
Min.
1.6
Typ.
Max.
Units
MHours
Conditions
MIL HDBK 217F, 25
º
C, Gnd Benign
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Model Selection Guide
Input
Model
Number
LD24-04-150
LD24-07-250
LD24-08-300
LD24-08-350
LD24-14-500
LD24-17-600
LD24-20-700
LD24-24-1000
Voltage
(VDC)
Range
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
7.0 - 30.0
Voltage
(VDC)
Range
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
2.0 - 28.0
Max
(mA)
150
250
300
350
500
600
700
1,000
Output
Current
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Maximum
Power
(W)
Ripple &
Noise
(mV P-P, Max)
Efficiency
(%, Max)
Package
Accuracy
(%)
±10
±8
±6
±5
±6
±7
±7
±7
4.2
7
8
8
14
17
20
24
200
200
200
200
250
250
250
300
95
95
95
95
95
95
95
95
14 -Pin DIP
14 -Pin DIP
14 -Pin DIP
14 -Pin DIP
16 -Pin DIP
16 -Pin DIP
16 -Pin DIP
16 -Pin DIP
Notes:
1. A reversed power source could damage the unit.
2. No connection should be made between input ground and the output.
3. These are step-down devices, the maximum output open voltage is
equal to the input voltage.
4. The V
ADJ
input should be left open if not used. Grounding V
ADJ
will shut the unit
down. Connecting V
ADJ
to V
IN
may damage the unit.
5. Exceeding the specified maximum output power could cause damage to the unit.
Typical Connection:
DC/DC Input
Connection Notes:
To comply with EN61000-4-5, a TVS should be installed before the input filter components. A 3.0SMCJ24A or SMCJ24A is recommended. The TVS max clamping voltage (@max peak pulse
40V. Exceeding the maximum input rating could damage the driver.
current V
C
) must be
The filter shown (C
1
, C
2
and L
1
) will help to meet conducted emission requirements. With the addition of the filter, the unit should meet the levels of EN 55015.
Typical Connection:
AC/DC Input
Connection Notes:
This is a distributed (or two-stage) AC connection. In this configuration, the AC line in (90 to 264 VAC) is connected to the
MPM-30D-15IS,
a compact 30W AC/DC power
supply. The
MPM-30D-15IS
is connected across its
±15
VDC outputs to provide a tightly regulated 30 VDC output at 1A. The 30 VDC output powers the LED driver.
The two stage approach can simplify the safety approval process (most AC/DC power supplies on the market are approved to EN 60950) and may increase design flex-
ibility. Besides the output power, other specifications to consider when selecting the input AC/DC supply would include input range, safety approvals, PFC rating (which
may be needed for various system energy ratings) and operating temperature range.
Note: The output current adjustment circuit shown in both connection diagrams is discussed on page 4.
292 Page Street Ste D Stoughton, MA 02072
•
TEL: (781) 344-8226
•
FAX: (781) 344-8481
•
E-Mail: sales@micropowerdirect.com
PWM Output Current Control
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An LED operates at its maximum efficiency when
operated at the rated drive current specified by
the manufacturer. Operating an LED at lower than
its rated forward current not only decreases the
system efficiency; but may cause color (or wave-
length) shifting. In illumination applications, this
could cause visible changes to lighting.
A preferred method is using pulse width modula-
tion (PWM). As shown at left, the output current
is adjusted by applying a PWM signal to the V
ADJ
input. By varying the signal duty cycle the average
output current is adjusted up or down. To avoid
visible flicker, the PWM signal should be greater
than 100 Hz.
For duty cycles (DPWM) between 0 and 1, the
output current is derived by the formula:
PWM Control Signals
I
NOM
= I
MAX
X D
PWM
The V
ADJ
input may be driven via an open collec-
tor transistor (as shown). The diode and resistor
suppress high amplitude negative spikes that may
be caused by the drain-source capacitance of the
transistor. Negative spikes on the control input of
the unit could cause errors in output current or
erratic operation.
The V
ADJ
input can also be driven by the open drain
output of a microcontroller. Again, any high amplitude
negative spikes that may be caused by the drain-
source capacitance of the FET must be supressed.
PWM Dimming Application
Get a full explanation
of this circuit in “Driving
LEDs”.
Available free at the
MPD
website
A simple method of achieving digital (or PWM) dimming is by using a 555 timer voltage drops to
1/3
V
CC
, the discharge pin goes high and C
6
begins to charge
to apply a series of pulses to the V
ADJ
input, as illustrated above. Again, we are again. The formulas for calculating the frequency and duty cycle are included
powering the LED driver with the
MPM-30D-15IS
AC power supply.
in the MPD application note “Driving
LEDs”.
The 555 operates over a supply voltage range of 4.5 VDC to 18VDC. Here it is
connected to the 15 VDC output of the
SR7805
switching regulator (also driven
by the
MPM-20S-24EPB).
Care should be taken to minimize ripple at the V
CC
input. Excess ripple could cause timing errors.
The diodes (D
1
and D
2
) allow duty cycles below 50% to be set. Diode D
1
bypasses
R
2
while C
6
is charging. Diode D
2
is optional (but recommended), essentially block-
ing R
2
during the charge period. Theoretically, this circuit will allow for duty cycles
over a range of about 5% to 95%. If manual adjustment is desired, a potentiometer
The timer is connected for astable (free run) operation. The frequency is set may be substituted for R
2
(with some adjustment of the circuit).
by R
1
, R
2
and C
6
. The timing capacitor (C
6
) charges through R
1
and D
2
. When The size of C
6
is generally not critical, but it should be as low leakage as pos-
it reaches the level of
2/3
V
CC
, the discharge pin (pin 7) goes low and C
6
will sible. In order to avoid excessive current flow through the internal discharge
discharge through D
1
and R
2
to the internal discharge transistor. When the C
6
transistor, it is recommended that R
1
be at least 5 k .
MicroPower Direct
•
292 Page Street Ste D Stoughton, MA 02072
•
TEL: (781) 344-8226
•
FAX: (781) 344-8481
•
E-Mail: sales@micropowerdirect.com
The output current of the unit can also be set by
adjusting the voltage level on the V
ADJ
input to a
value between 0.3V to 1.25V (I
OUT
will vary from
25% to 100% of rated output current). Care must
be taken not to exceed 1.25V on this input, or the
driver may be damaged.
The simple analog circuit at left uses the
F2506RW,
a 30W, dual 15V output DC/DC converter. Operating
from an input line of 12 VDC, the converter sets the
input to the LED driver at 30 VDC.
The POL regulator, driven off the same input line
maintains the control voltage (for the V
ADJ
input) at
5 VDC. The resister network of R
1
and R
2
can now
be used to set the output current level of the LED
driver. This level is equal to:
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Analog Output Current Control
V
ADJ
=
R
2
X V
CTRL
R
1
+ R
2
In the second circuit, the input DC/DC has been changed to
the
F2506RU.
The 4:1 input of the converter allows for wider
input bus levels (in this case 24 VDC). The POL regulator
is also replaced by the shunt regulator (D
1
). The regulator,
connected in parallel with the resistor network, will maintain
the voltage across R
2
and R
3
at 2.5 VDC, insuring that the
1.25 VDC limit on the V
ADJ
pin will not be exceeded.
When using the analog control input, the nominal output
current is equal to:
Analog Output Current Control
(7 - 30 VDC IN)
I
NOM
= I
MAX
x
V
ADJ
1.25
The V
ADJ
input should be left open if not used. Grounding
V
ADJ
will shut the unit down. Connecting V
ADJ
to directly
to +V
IN
may damage the unit.
Mechanical Dimensions
- 16 Pin DIP
Mechanical Dimensions
- 14 Pin DIP
Pin Connections
- 16 Pin DIP
Pin
1
2
3
7
8
Pin Connections
- 14 Pin DIP
Pin
Function
-V
IN
-DC Supply
PWM, On/Off
V
ADJ
-LED LED Cathode Conn.
8
14
+LED
+V
IN
LED Anode Conn.
+DC Supply
LED Anode Conn.
LED Anode Conn.
+DC Supply
+DC Supply
1
2
7
Function
-V
IN
-DC Supply
-DC Supply
-V
IN
PWM, On/Off
V
ADJ
-LED LED Cathode Conn.
-LED LED Cathode Conn.
9
10
15
16
+LED
+LED
+V
IN
+V
IN
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•
Notes:
•
All dimensions are typical in inches (mm)
•
Tolerance x.xx = ±0.02 (±0.50)
•
Pin 1 is marked by a “dot” or indentation on the top of the unit