Performance Summary; Quick Start Procedure - Linear Technology DC1759A Demo Manual

DEMO MANUAL DC1759A

PERFORMANCE SUMMARY

PARAMETER
Input Voltage Range
Output Voltage V
OUT1
Output Voltage V
OUT2
Per-Channel Maximum Continuous Output Current
Default Operating Frequency
Resistor Programmable Frequency Range
External Clock Sync. Frequency Range
Efficiency of Channel 1
Efficiency of Channel 2
Load Transient of Channel 1
Load Transient of Channel 2

QUICK START PROCEDURE

Demonstration circuit 1759A is easy to set up to evalu-
ate the performance of the LTM4620AEV. Please refer to
Figure 2 for proper measurement setup and follow the
procedure below:
1. Place jumpers in the following positions for a typical
application:
JP1 JP2
MODE RUN1
CCM ON
2. With power off, connect the input power supply, load
and meters as shown in Figure 2. Preset the load to 0A
and V supply to 12V.
IN
3. Turn on the power supply at the input. The output
voltage in channel 1 should be 3.3V ±1.5% (3.2505V
~ 3.3495V) and the output voltage in channel 2 should
be 5V ±1.5% (4.925V ~ 5.075V).
4. Once the proper output voltage is established, adjust the
load within the operating range and observe the output
voltage regulation, output voltage ripple, efficiency and
other parameters. Output ripple should be measured
at J1 and J2 with BNC cables. 50Ω termination should
be set on the oscilloscope or BNC cables.
2
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CONDITION
V = 5.5V ~ 16V, I
IN
V = 5.5V ~16V, I
IN
Derating is Necessary for Certain V
See Data Sheet for Detail.
V = 12V, V
IN
V = 12V, V
IN
V = 12V, V
IN
V = 12V, V
IN
JP3 JP4 JP5
RUN2 TRACK1 TRACK2
SEL. SEL.
ON SOFT- SOFT-
START START
= 25°C)
A
= 0A ~ 13A, JP1: CCM
OUT1
= 0A ~ 13A, JP1: CCM
OUT2
, V
IN OUT
= 3.3V, I = 13A, f
OUT1 OUT1 SW
= 5V, I = 13A, f
OUT2 OUT2 SW
= 3.3V, I = 6.5A ~ 13A
OUT1 SETP
= 5V, I = 6.5A ~ 13A
OUT2 SETP
5. (Optional) For optional load transient test, apply an
adjustable pulse signal between IOSTEP CLK and GND
test point. Pulse amplitude (3V ~ 3.5V) sets the load
step current amplitude. The output transient current
can be monitored at the BNC connector J3 (15mV/A).
The pulse signal should have very small duty cycle
(<1%) to limit the thermal stress on the transient load
circuit. Switch the jumper resistors R34 or R35 (on the
JP6
backside of boards) to apply load transient on channel 1
CLKOUT
PHASE
or channel 2 correspondingly.
90°
6. (Optional) LTM4620A can be synchronized to an external
clock signal. Place the JP1 jumper on EXT_CLK and
apply a clock signal (0V ~ 5V, square wave) on the
CLKIN test point.
7. (Optional) The outputs of LTM4620A can track another
supply. The jumpers JP4 and JP5 allow choosing soft-
start or output tracking. If tracking external voltage is
selected, the corresponding test points, TRACK1 and
TRACK2, need to be connected to a valid voltage signal.
8. (Optional) LTM4620A can be configured for a 2-phase
single output at up to 26A on DC1759A. Install 0Ω
resistors on R14, R17, R28, R39 and remove R7,
R19. Output voltage is set by R25 based on equation
V = 0.6V(1 + 60.4k/R25).
OUT
VALUE
5.5V ~ 16V
3.3V ±1.5%
5V ±1.5%
and Thermal Conditions, 13A (per-Channel)
750kHz
250kHz to 780kHz
400kHz to 780kHz
= 750kHz 91.7% See Figure 3
= 750kHz 93.8% See Figure 4
See Figure 5
See Figure 6
dc1759af