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 60V Input Range
Max Input Voltage
Input Filter
•
Efficiency to 97%
Output
•
Miniature MiniDIP Case
Parameter
Output Voltage Range
•
300 mA to 1A Output
Output Current
•
Meets EN 60950
Output Current Accuracy
Output Power
•
950 kHrs MTBF
Efficiency
•
Digital & Analog Dimming!
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)
Physical
Case Size
Case Material
Weight
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
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.
0.5 Sec. Max
Internal Capacitor
Conditions
Min.
Typ.
V
IN
= 60V
2
See Model Selection Guide
See Model Selection Guide
See Model Selection Guide
See Model Selection Guide
20
See Model Selection Guide
Max.
60.0
65.0
Units
VDC
VDC
Max.
57
Units
VDC
470
500
µF
kHz
%/
º
C
º
C/W
±0.03
Natural Convection
+30
Regulated At Rated Output Current
Conditions
Ambient
Case
Min.
-40
Typ.
+25
Max.
+85
+110
+125
95
260
Units
º
C
º
C
-40
Free Air Convection
RH, Non-condensing
1.5 mm From Case For 10 Sec
%
ºC
1.25 x 0.80 x 0.49 Inches (31.75 x 20.32 x 12.45 mm)
Non-Conductive Black Plastic (UL94-V0)
0.622 Oz (17.7g)
Conditions
Min.
Typ.
Max.
Units
Open or 0.3V < V
ADJ
<1.25V
V
ADJ
<0.15V
1
mA
100
µA
Typ.
Max.
1.0
Units
kHz
nS
nS
Units
VDC
%
VDC
mA
V
ADJ
= 1.25V
V
IN
= 60V
Conditions
Recommended Maximum
Min.
200
200
Conditions
At V
ADJ
Input (Pin 4)
On
Off
V
ADJ
= 1.25V
Radiated/Conducted
Class A
Class A
Class A
Min.
0.3
25
0.20
0.15
MicroPower Direct
292 Page Street
Suite D
Stoughton, MA 02072
USA
T:
(781) 344-8226
F:
(781) 344-8481
E:
sales@micropowerdirect.com
W:
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Typ.
Max.
1.25
100
0.30
0.25
1.0
EN 55015 (CISPR22)
IEC/EN 61000-4-2, -6, -8
IEC/EN 61000-4-3
IEC/EN 61000-4-4
EN61547
Min.
950
Typ.
Max.
Units
kHours
Conditions
MIL HDBK 217F, 25
º
C, Gnd Benign
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Model Selection Guide
Model
Number
LD48-09-150
LD48-14-250
LD48-17-300
LD48-20-350
LD48-29-500
LD48-34-600
LD48-40-700
LD48-48-1000
Input
Voltage
(VDC)
Range
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
7.0 - 60.0
Output
Voltage
(VDC)
Range
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
2.0 - 57.0
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Current
Max
(mA)
Accuracy
(%)
150
±8
250
±7
300
±6
350
±5
500
±5
600
±5
700
±5
1000
±5
Maximum
Power
(W)
Ripple &
Noise
(mV P-P, Max)
Efficiency
(%, Typ)
9
14
17
20
29
34
40
48
150
200
250
300
400
450
500
800
97
97
97
97
97
97
97
97
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 3.0SMCJ48A or SMCJ48A is recommended. The TVS max clamping voltage (@max peak pulse
60V. This will prevent any surge from exceeding the maximum input of the driver (65 VDC). 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-04S-12,
a miniature 4W AC/DC power
supply. The
MPM-04S-12
provides a tightly regulated 12 VDC output at 333 mA. The 12 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
to apply a series of pulses to the V
ADJ
input, as illustrated above. The 555 oper-
ates over a supply voltage range of 4.5 VDC to 15VDC. Here it is connected
to the 12 VDC output of the
SR7805
switching regulator (this is also the V
IN
of the LED driver). Care should be taken to minimize ripple at the V
CC
input.
Excess ripple could cause timing errors.
again. The formulas for calculating the frequency and duty cycle are included
in the MPD application note “Driving
LEDs”.
The diodes (D
1
and D
2
) allow duty cycles below 50% to be set. Diode D
1
bypasses R
2
while C
4
is charging. Diode D
2
is optional (but recommended),
essentially blocking R
2
during the charge period. Theoretically, this circuit will
allow for duty cycles over a range of approximately 5% to 95%. If manual
The timer is connected for astable (free run) operation. The frequency is set adjustment is desired, a potentiometer may be substituted for R
2
(with some
by R
1
, R
2
and C
4
. The timing capacitor (C
4
) charges through R
1
and D
2
. When adjustment of the circuit).
it reaches the level of
2/3
V
CC
, the discharge pin (pin 7) goes low and C
4
will
discharge through D
1
and R
2
to the internal discharge transistor. When the C
4
The size of C
4
is generally not critical, but it should be as low leakage as pos-
voltage drops to
1/3
V
CC
, the discharge pin goes high and C
4
begins to charge sible. In order to avoid excessive current flow through the internal discharge
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.
A simple analog circuit using two low cost,
switching regulators is shown at left. Work-
ing from inputs that can range from 15 to 32
VDC,the top regulator (SR
1
) keeps the input to
the LED driver at 12 VDC.
The other regulator (SR
2
), 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 cur-
rent 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 5 VDC regulator (SR
2
)
is replaced by the shunt regulator (D
1
) circuit
connected in parallel with the resistor network.
The regulator 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. This
circuit will work for inputs between 7VDC and
approximately 36 VDC. For inputs between 36
VDC and 60 VDC, a zener diode (D
2
) has been
added.
When using the analog control input, the nominal
output current is equal to:
Analog Output Current Control
(7 - 36 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. Connect-
ing V
ADJ
to directly to +V
IN
may damage the unit.
Analog Output Current Control
(36 - 60 VDC IN)
Mechanical Dimensions
Pin Connections
Pin
2
3
4
9
11
14
16
22
23
-V
IN
-V
IN
V
ADJ
Function
-DC Supply
-DC Supply
PWM, On/Off
-LED LED Cathode Conn.
-LED LED Cathode Conn.
+LED
+LED
+V
IN
+V
IN
LED Anode Conn.
LED Anode Conn.
+DC Supply
+DC Supply
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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
嵌入式系统
