ISL6401EVAL1 Intersil, ISL6401EVAL1 Datasheet - Page 3

• Manufacturer Part Number: ISL6401EVAL1
• Description: EVALUATION BOARD ISL6401
• Manufacturer: Intersil

Specifications of ISL6401EVAL1

• Main Purpose: DC/DC, Negative Inverter
• Outputs And Type: 2, Isolated
• Power - Output: 11.5W
• Voltage - Output: -24V, -72V
• Current - Output: 120mA, 120mA
• Voltage - Input: 5V, 12V
• Regulator Topology: Inverting
• Board Type: Fully Populated
• Utilized Ic / Part: ISL6401
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Output Performance
Output Ripple - Figure 2 shows the output voltage ripple
for VOUT1 and VOUT2 both at 100mA load.
Transient Response - Figures 3 and 4 show the transient
performance of the each output for a step load from 0mA to
100mA.
Oscillator
Switching Frequency - The gate driver output switching
frequency can be programmed from 50kHz to 600kHz by
adjusting the capacitor value on the CT pin (C5). Figure 5
can be used as a guideline in selecting the capacitor value
required for a given frequency.
VOUT2
20mV/DIV
VOUT1
50mV/DIV
IOUT1
50mA/DIV
VOUT2
200mV/DIV
IOUT2
50mA/DIV
VOUT1
20mV/DIV
FIGURE 2. OUTPUT 1 AND 2 RIPPLE VOLTAGE
FIGURE 3. VOUT1 TRANSIENT RESPONSE
FIGURE 4. VOUT2 TRANSIENT RESPONSE
2ms/DIV
2ms/DIV
10µs/DIV
3
Application Note 1082
External Synchronization - The internal oscillator can be
synchronized by an external clock connected to the SYNC
pin (P6). Program the free running frequency of the oscillator
to be 10% slower than the desired synchronous frequency.
The external clock signal should have a minimum pulse
width of 20ns.
Shutdown
When the SD pin (P5) is pulled low, the PWM is turned off
and the output capacitors discharge. A typical shutdown
waveform using the SD pin is shown in Figure 6.
Conclusion
The ISL6401EVAL1Z evaluation board is a flyback reference
design optimized to provide a high performance, low-cost
solution for RSLIC Ring and Talk power supplies in VoIP
application. It has the capability of evaluating device operation
with loads that simulate one, two, three, or four line operation.
References
1. ISL6401 Datasheet (“ISL6401: Synchronizing Current
Mode PWM for Subscriber Line Interface Circuits”), Intersil
Corporation, FN9007. For Intersil documents available on
the web, see http://www.intersil.com/
600
500
400
300
200
100
FIGURE 5. OUTPUT SWITCHING FREQUENCY vs CT
VOUT1
20V/DIV
0
VOUT2
20V/DIV
FIGURE 6. OUTPUT SHUTDOWN WAVEFORMS
82
120
180
10ms/DIV
250
CAPACITANCE (pF)
300
390
510
610
January 30, 2009
820
AN1082.2
1200