DTL Series
OBSOLETE PRODUCT
DTL4A Model
Digitally Programmable, 10A/150V
100 Watt, Electronic Loads
Features
■
12-bit, optically isolated (500Vdc),
CMOS/TTL-compatible serial input
0-10 Amp output in 2.44mA increments
10MΩ minimum output impedance
Output voltage to 150 Volts
Output power to 100 Watts
±3mA offset error; ±0.1% gain error
100µsec full-scale step response
Update rates to 20kHz
Operate in parallel for higher power
Miniature, 2" x 2" metal package
■
■
■
■
■
■
■
■
■
Applications
■
■
■
■
■
■
Static/dynamic power-supply burn-in
Power-supply test and characterization
Battery capacity testing
Current-source testing
Capacitor discharge testing
Real-time load simulation
DATEL’s new DTL4A is an optically isolated, digitally programmable, serial-input,
electronic load. It is essentially a digitally controlled current source that can sink
currents from 0 to 10 Amps, at loading voltages from 2.5 to 150 Volts, up to a maximum
power of 100 Watts. The DTL4A is packaged in a thermally ef cient, 2" x 2" x 0.5"
metal package that incorporates an aluminum baseplate with through-hole spacers
for easy pcb mounting and/or external heat-sink attachment.
The DTL4A accepts a serialized, 12-bit, CMOS/TTL-compatible, digital input word
easily generated by any standard digital I/O card. The DTL4A buffers and then
optically isolates (500Vdc) the digital input data before storing it in a register and
presenting it to an on-board, 12-bit, digital-to-analog (D/A) converter. The D/A output
drives a near-ideal (10MΩ minimum output impedance), voltage-controlled current
source. One LSB (least signi cant bit) of the D/A converter corresponds to a 2.4mA
increment (0.024% of 10A) in load current.
The DTL4A features a max. ±3mA offset error and a max. ±0.1% gain error. It
has an impressive full-scale step response time of 100µsec and can be operated
dynamically at update rates up to 20kHz. Powered by a single +5V supply, the DTL4A
draws a mere 150mA (maximum).
While operating in the constant-current mode up to 10 Amps (100W max. power),
the output compliance voltage of the DTL4A is 2.5 to 150 Volts. Should the output/load
voltage drop below the 2.5V minimum required for proper biasing, an internal monitoring
circuit activates the DTL4A's output Fault line. See DATEL’s DTL2A-LC for compliance
voltages as low as 0.6V.
DTL4A’s and other electronic loads, controller boards, and software from DATEL
are outstanding building-block components for power-supply burn-in and test systems.
They are an extremely reliable, cost-effective solution that enables you to quickly
con gure impressively accurate systems.
INPUT
BUFFERS
CONTROL STROBE (CS)
OPTO
ISOLATORS
+LOAD
CLOCK (CLK)
DATA
LATCH
12-BIT
D/A
AMPLIFIER
AND
CURRENT
SENSOR
–LOAD
LATCH DATA (LD)
–LOAD
+LOAD
POWER DEVICE
UNDER TEST
SERIAL DATA INPUT (SDI)
+5V SUPPLY
GROUND
ISOLATED
DC/DC
CONVERTER
UNDERVOLTAGE
DETECTION
FAULT
Figure 1. Simplified Schematic
DTL Series
1 0 0 WAT T, S E R I A L - I N P U T E L E C T R O N I C L OA D S
Performance Specifications and Ordering Guide
Input
Resolution
(Bits)
12
Logic
Compatibility
CMOS/TTL
➃
➀
Output
Model
DTL4A
Current
(Amps)
0-10
Resolution
(mA)
➁
2.44
Compliance
Voltage
(Volts)
➂
2.5-150
Power
(Watts)
0-100
Package
(Case, Pinout)
C24, P31
➀
Typical at T
A
= +25°C with nominal +5V supply voltage unless noted.
➁
The smallest increment/decrement in output current is defined by one LSB (least significant bit) of the 12-bit
digital input word. One LSB is equal to full scale (FS) divided by 4096 which corresponds to 0.0244% of 10A or 2.44mA.
➂
For proper operation, the unit's output/load voltage must remain within this range. Voltages greater than the listed
maximum can damage the device. Voltages less than the minimum provide insufficient bias for the output stage
and will result in unpredictable or no operation. See Output Compliance Voltage and the Fault Line for details.
➃
See Performance/Functional Specifications for details.
PA R T N U M B E R S T R U C T U R E
M E C H A N I C A L S P E C I F I C AT I O N S
DTL
DATEL
Electronic Load
4 A
A-Series
High Reliability
0.50
(12.70)
2.00
(50.80)
ALUMINUM BASEPLATE
METAL CASE
Case C24
Voltage Range:
4 = 2.5 to 150V
0.20 MIN
(5.08)
0.040 ±0.002 DIA.
(1.016 ±0.051)
1.800
(45.72)
1.640
(41.66)
0.060 ±0.002 DIA.
(1.524 ±0.051)
0.10
(2.54)
0.08
(2.03)
T E M P E R AT U R E D E R AT I N
7
100
90
80
8
6
1.20
(30.48)
6 EQ. SP. @
0.200 (5.08)
5
4
3
2
1
9
2.00
1.640
(41.66) (50.80)
Output Power/Load (Watts)
10
70
60
50
40
30
20
11
0.40
(10.16)
BOTTOM VIEW
#4-40 CLEAR THRU
(TYP. 4 PL)
0.22
(5.59)
I/O Connections
Pin
Function P31
Fault
Ground
+5 Volt Supply
Latch Data (LD)
Serial Data In (SDI)
Clock (CLK)
Pin
7
8
9
10
11
Function P31
Control Strobe (CS)
–Load
–Load
+Load
+Load
1
2
0
10
20
30
40
50
60
70
80
90
100
10
Baseplate Temperature (°C)
3
4
5
The horizontal axis of the above chart references the temperature of the DTL4A’s alumi-
num baseplate. The device can continually dissipate up to 100 Watts if the baseplate
is maintained at or below +50°C. At +25°C ambient temperature, with no heat sink or
supplemental air flow, the DTL4A can reliably dissipate a continuous 10 Watts.
6
Contact DATEL for Heat Sink information.
2
1 0 0 WAT T, S E R I A L - I N P U T E L E C T R O N I C L OA D S
DTL4A Model
Performance/Functional Specifications
Typical @ T
A
= +25°C with nominal +5V supply voltage, unless noted.
Digital Inputs/Outputs
Logic Compatibility
(Pins 1, 4-7)
Input Logic Levels:
Logic "1"
Logic "0"
Input Logic Loading:
Logic "1" (I
IH
@ V
IH
= 5 Volts)
Logic "0" (I
IL
@ V
IL
= 0 Volts)
Output Logic Levels:
Logic "1" (@ 150µA)
Logic "0" (@ 1.6mA)
Timing
Current:
Range
Resolution
➀
Accuracy
➅
Voltage Range
➁
Power Range
Impedance
Offset Error
➂
Gain Error
Isolation Voltage:
Digital Inputs/Output to ±Load
Any Pin to Case
Isolation Resistance
Output Slew Rate
Output Settling Time
➃
Digital Input Update Rate
Power Supply Range
(+V
CC
, Pin 3)
Power Supply Current
Operating Temperature
➄
Storage Temperature
Humidity (Non-condensing)
Altitude Above Sea Level
Dimensions
Shielding
Case Material
Pin Material
Mounting Holes
Weight
CMOS/TTL
+2 Volts, minimum
+0.8 Volts, maximum
20µA, maximum
–0.6mA, maximum
+3.5 Volts, minimum
+0.4 Volts, maximum
See Timing Diagram
➀
The smallest increment/decrement in output current is defined by one LSB (least significant
bit) of the 12-bit digital input word. One LSB is equal to full scale (FS) divided by 4096 which
corresponds to 0.0244% of 10A or 2.44mA.
➁
For proper operation, the unit's output/load voltage must remain within this range. Voltages
greater than the listed maximum can damage the device. Voltages less than the minimum
provide insufficient bias for the output stage and will result in unpredictable or no operation.
See Output Compliance Voltage and the Fault Line for details.
➂
Offset error is defined as the current sunk/sourced by the DTL4A’s output, under any output
voltage conditions, when the digital input word is all "0's."
➃
Full scale step (10 Amps) settling to within ±2.44mA of its final value.
➄
See Temperature Derating.
➅
Applies over all specified ranges/combinations of load voltage/current, operating temperature,
and V
CC
.
Absolute Maximum Ratings
Power Supply Voltage
(+V
CC
, Pin 3)
Digital Input Voltage
(Pins 4-7)
–0.5 to +5.5 Volts
–0.5 to +5.5 Volts
No protection
No protection
Yes (See Fault Line)
+105°C
–40 to +125°C
+300°C
Output
0-10 Amps
0.024%FS (2.44mA)
±1%, maximum
2.5-150 Volts
0-100 Watts
10MΩ, minimum
±3mA, maximum
±0.1%, maximum
500Vdc, minimum
500Vdc, minimum
100MΩ, minimum
Output Reverse-Polarity Protection
Output Overvoltage Protection
Output Undervoltage Protection
Case Temperature
Storage Temperature
(Ambient)
Lead Temperature
(soldering, 10 sec.)
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied.
Dynamic Performance
±10A/µsec, minimum
100µsec
to 20kHz
TECHNICAL NOTES
Overview
The DTL4A is a digitally programmable, CMOS/TTL-compatible, serial-input
current sink. It’s output/load current range is 0 to 10 Amps (in 2.44mA
increments), over a compliance voltage range of 2.5 to 150 Volts and an output/
load power range of 0 to 100 Watts. The device’s digital I/O coding is straight
binary (see table below). A digital input of all "0’s" forces a load current of 0
Amps. A digital input of all "1’s" forces a load current of 9.99756 Amps.
In a typical power-supply test or burn-in application, the output pins of the
device under test (DUT) are connected to the DTL4A’s +Load (pins 10 and 11)
and –Load (pins 8 and 9) outputs. The DTL4A’s operation is controlled by its
four digital input lines (Serial Data In, Clock, Latch Data and Control Strobe).
Serial Input Data Word
MSB
1111
1100
1000
0111
0100
0010
0000
0000
1111
0000
0000
1111
0000
0000
0000
0000
LSB
1111
0000
0000
1111
0000
0000
0001
0000
Power Requirements
+4.75-5.25 Volts (+5V nominal)
110mA typ., 150mA max.
Environmental
–40 to +100°C (Case)
–40 to +125°C (Ambient)
to 95%
10,000 feet
Physical
2" x 2" x 0.5" (51 x 51 x 12.7mm)
6-sided (Connected to pin 2)
Tin-plated steel shell with
aluminum baseplate
Brass, solder coated
Through-hole spacers, #4-40 clearance
1.9 ounces (54 grams)
Load Current (Amps)
DTL4A
9.9976
7.5000
5.0000
4.9976
2.5000
1.2500
0.0024
0.0000
Mapping of the Serial-Input Data to Load Current
3
DTL Series
1 0 0 WAT T, S E R I A L - I N P U T E L E C T R O N I C L OA D S
Initialization
Preparing the DTL4A to accept new digital data is accomplished by applying
logic "1's" to Control Strobe (CS, pin 7), Latch Data (LD, pin 4) and Clock
(CLK, pin 6) with all signals present and stable for a minimum of 1µsec.
During this interval, it does not matter whether or not data is present on the
Serial Data In (SDI, pin 5) line.
Serial Data
Following initialization, the 12-bit digital word representing the desired output
current is applied to the SDI pin. The serial data should appear starting with
the most significant bit (MSB, bit 1, D11) and ending with the least significant
bit (LSB, bit 12, D0). With each data bit present and stable on the SDI line,
the CLK must be toggled through a low-to-high transition to register that bit.
Twelve rising clock edges, at rates up to 500kHz, are required to clock all 12
digital bits into the DTL4A’s input register.
Latching Data and Presenting It to the D/A
After loading the LSB, the serial data word is latched by bringing the Control
Strobe (pin 7) high and then toggling the Latch Data pin (pin 4) through a
high-low-high sequence. Approximately 100µsec later, the output current will
settle to its final desired value.
Software: C Language
The following steps describe a typical timing sequence when using the
DTL4A’s 4 digital inputs and a programming language such as C. Using 4 bits
of a typical 8-bit port, assign BIT_0 to the Control Strobe (CS, pin 7), BIT_1
to Latch Data (LD, pin 4), BIT_2 to Serial Data In (SDI, pin 5), and BIT_3
to the Clock (CLK, pin 6).
1. Initialize with Control Strobe, Latch Data, and Clock high:
BIT_0 = 1, BIT_1 = 1, BIT_2 = X (don’t care), BIT_3 = 1
2. Bring the Control Strobe low.
BIT_0 = 0
3. Apply the MSB (D11) of the serial data word to Serial Data In.
BIT_2 = 0 or 1
4. Toggle the Clock high-low-high.
BIT_3 = 1 to 0 to 1
5. Apply D10 of the serial data word to Serial Data In.
BIT_2 = 0 or 1
6. Toggle the Clock high-low-high.
BIT_3 = 1 to 0 to 1
7. Repeat the process for remaining data bits D9 through D0.
8. Drive the Control Strobe high.
BIT_0 = 1
9. Toggle the Latch Data input high-low-high.
BIT_1 = 1 to 0 to 1.
Output Compliance Voltage and the Fault Line
For proper operation, the DTL4A’s output/load voltage must
always be between 2.5 and 150 Volts. The device cannot be used
to directly load low-voltage, e.g. 1.8V or 2.5V, power components or
to simulate a true short circuit (0 Volts). Voltages greater than 150V
can damage the device. Voltages <2.5V will result in insufficient
biasing of the output current source and consequently unpredict-
able or no operation. Accordingly, we have installed an internal
output/load-voltage monitoring circuit. If the output/load voltage
drops below 2.5V and the DTL4A’s output is at risk of becoming
disabled, the Fault line activates.
The Fault line is an optically isolated, active-low function with
an open-collector output (internal 10kΩ pull-up resistor to +5V).
Under normal conditions, its output is high (logic "1"). Under fault
conditions (V
OUT
< 2.5V), its output drops to a logic "0." There is
no output/load-voltage monitoring circuit for voltages greater than
150V, and operation above 150V can damage the device.
An "offset supply" can be inserted between the DTL4A’s –Load
output (pins 8 and 9) and the power device under test (DUT)
to "translate" the DTL4A’s 147.5V output/load voltage range. The
offset supply must have adequate current capabilities and be con-
nected with the polarities indicated in Figure 2 below. Under no
circumstances should the voltage across the DTL4A’s output be
allowed to experience a polarity reversal.
If a 5V/20A offset supply is inserted as shown, the range of
DUT voltages will be –2.5 to +145 Volts. Such a configuration
can be used for true short-circuit testing. A mechanical relay can
be used to short the outputs of the DUT while the offset supply
ensures the DTL4A always sees at least 5 Volts across its outputs.
+LOAD
11
10
+
DUT
5V
9
+
–
SHORT
CIRCUIT
RELAY
DTL4A
–LOAD
8
–
Figure 2. An "Offset Supply" Enables
True Short-Circuit Testing
Thermal Considerations
The DTL4A can reliably handle 100W loads if its case temperature is
maintained at or below +50°C. With no heat sinking or auxiliary cooling, the
device can only handle loads up to 10 Watts. Please refer to the Temperature
Derating Curve for additional information. DATEL’s Electronic Load Applica-
tions Engineers can assist you in developing heat-sink solutions for your
higher-power DTL4A applications. Please contact us for details.
4
1 0 0 WAT T, S E R I A L - I N P U T E L E C T R O N I C L OA D S
DTL4A Model
t
dh
SDI
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
t
ds
t
in
CLK
t
css
t
cl
t
ch
t
csh
CS
t
ld1
LD
t
ld2
t
ldw
Timing
CLK
Min.
–
1
1
1
1
2
2
2
0.5
0.5
Typ.
–
–
–
–
–
–
–
–
–
–
Max.
200
–
–
–
–
–
–
–
–
–
Units
kHz
µsec
µsec
µsec
µsec
µsec
µsec
µsec
µsec
µsec
t
in
t
cl
= t
ch
t
css
t
csh
t
ld1
t
ld2
t
ldw
t
ds
t
dh
Figure 3. DTL4A Timing Diagram
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
This product is subject to the following
operating requirements
and the
Life and Safety Critical Application Sales Policy:
Refer to:
http://www.murata-ps.com/requirements/
Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply
the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without
notice.
© 2012 Murata Power Solutions, Inc.
www.murata-ps.com/support
5
京公网安备 11010802033920号
EEWORLD
