MAX15005AEVKIT+ Maxim Integrated Products, MAX15005AEVKIT+ Datasheet - Page 4

• Manufacturer Part Number: MAX15005AEVKIT+
• Description: KIT EVAL FOR MAX15005A
• Manufacturer: Maxim Integrated Products

Specifications of MAX15005AEVKIT+

• Main Purpose: DC/DC, Step Up or Down
• Outputs And Type: 3, Isolated
• Voltage - Output: 3V, 110V, 60V
• Current - Output: 650mA, 55mA, 12mA
• Voltage - Input: 6.5 ~ 16V
• Regulator Topology: Flyback
• Frequency - Switching: 100kHz
• Board Type: Fully Populated
• Utilized Ic / Part: MAX15005A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MAX15005A Evaluation Kit
The MAX15005A controller switches at a fixed 100kHz
frequency and is set by resistor/capacitor network R1
and C5. The switching duty cycle is varied to control
energy transfer to the outputs. The maximum duty cycle
is 50% for the EV kit’s discontinuous current-mode fly-
back design.
The MAX15005A EV kit features a jumper (JU1) that
can be used to shut down the flyback DC-DC convert-
er. An alternate shutdown method (remote control) can
be done with a user-supplied relay contact connected
to pin 2 of jumper JU1 of the EV kit. Table 1 shows
jumper options.
Table 1. Jumper JU1 Shutdown Mode
The MAX15005A can be synchronized to an external
TTL/CMOS square-wave clock source. The 2-pin
jumper (JU2) selects the SYNC mode of operation or
100kHz internal frequency for the MAX15005A. Table 2
shows jumper options.
The TTL/CMOS square-wave clock source (from
105kHz to 130kHz) must provide the following signal
qualities:
•
•
•
•
4
Not installed
Not installed
POSITION
Installed
SHUNT
_______________________________________________________________________________________
Output voltage:
Output frequency = 105kHz to 130kHz
Minimum positive-pulse width = 50ns
Connect the external square-wave clock to the
SYNC and PGND pads. Refer to the MAX15005A
data sheet for more information on the SYNC pin.
Logic-low = 0 to 0.8V
Logic-high = 2V to 5.5V
Shutdown Mode (Jumper- or Remote-
through resistor R18
connected between
UVLO resistors R17
Pulled low to PGND
and R18 determine
startup voltage
Relay contacts
ON/OFF PIN
JU1 pin 2
Control Method)
MAX15005A enabled
MAX15005A EV KIT
Shutdown mode
Remote mode
SYNC Mode
OUTPUT
The EV kit features current limiting for the transformer’s
primary current. The MAX15005A IC turns off switching
MOSFET N1 when the voltage at the MAX15005A CS
pin reaches 0.3V. Current-sense resistor R6 (0.07Ω)
limits the transformer peak primary current to 4.2A
(0.3V / 0.07Ω = 4.2A). To evaluate a lower current limit,
current-sense resistor R6 must be replaced with a
different surface-mount resistor (2010 size), as deter-
mined by the following equation:
where I
mary current.
The MAX15005A EV kit features a brownout and input-
supply startup UVLO circuit that prevents operation
below the programmed input-supply-start voltage.
Resistors R17 and R18 set the input UVLO threshold of
the EV kit. To change the input UVLO voltage, replace
resistor R17 (or R18) with another surface-mount resis-
tor (0603 size). Using the desired startup voltage, resis-
tor R17 is then found by the following equation:
where VIN
the EV kit starts at, and resistor R18 is typically in the
50kΩ range (47.5kΩ default). Refer to the Startup
Operation/UVLO/ON/OFF section of the MAX15005A
data sheet for additional information on the ON/OFF pin
of the MAX15005A IC.
Table 2. Jumper JU2 SYNC Mode
Functions
Not installed
POSITION
Installed
SHUNT
Evaluating Other Current Limits, Input
PRIMARY
STARTUP
UVLO, and Output OVP Shutdown
R17
Connected to SGND
external TTL/CMOS
source at the SYNC
square-wave clock
R6 = (0.300V/I
Connected to an
and SGND pads
is the transformer’s maximum peak pri-
=
SYNC PIN
is the desired startup voltage that
⎛
⎜
⎝
(
VIN
1.230V
STARTUP
PRIMARY
Input UVLO (ON/OFF)
)
Synchronization mode
OPERATING MODE
Internal clock mode
(synchronized to an
−
(100kHz set by R1
Current Limiting
1 x R18
)
external clock
⎞
⎟
⎠
MAX15005A
frequency)
and C5)