MAX8569EVKIT+ Maxim Integrated Products, MAX8569EVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX8569EVKIT+
• Description: EVALUATION KIT FOR MAX8569
• Manufacturer: Maxim Integrated Products

Specifications of MAX8569EVKIT+

• Main Purpose: DC/DC, Step Up
• Outputs And Type: 1, Non-Isolated
• Current - Output: 200mA
• Voltage - Input: 1.5 ~ 5.5V
• Regulator Topology: Boost
• Board Type: Fully Populated
• Utilized Ic / Part: MAX8569
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Table 1. Jumper JU1 Functions (SHDN Control)
The MAX8569B provides a power-on reset output (RST)
that goes high when the output reaches 90% of the
nominal voltage. RESET_ pulls low when the output is
below 90% of the nominal voltage.
Place a shunt between pins 2-3 of jumper JU_ to shut
down the MAX8569_ and reduce the input current to
less than 1µA. During shutdown, the BATT_ input is
connected to VOUT_ through the inductor and the inter-
nal synchronous rectifier. This allows the input battery
(rather than a separate backup battery) to provide
backup power for devices such as a microcontroller,
SRAM, or real-time clock, without the usual diode for-
ward drop. Place a shunt between pins 1-2 of jumper
JU_ to enable the IC for normal operation.
The SHDN trip threshold of the MAX8569_ may be used
as an input-voltage detector that disables the IC when
the battery voltage falls below a set level. To use the
input-voltage-detector circuit, remove the shunt from
jumper JU_. The SHDN trip threshold is 1.228V (typ). A
resistor-divider sets the battery-detection voltage
Detailed Description of Hardware
SHUNT POSITION
1-2
2-3
_______________________________________________________________________________________
Power-On Reset ( RST )
Low-Battery Cutoff
Shutdown
Connected to BATT
Connected to GND
SHDN PIN
MAX8569 Evaluation Kit
(R1/R2 and R7/R8). The low-battery threshold is facto-
ry-set at 1.5V. To change the threshold, replace R1/R7.
Calculate R1/R7 (R
where V
shuts down and V
The MAX8569 EV kit is easily modified to evaluate the
MAX8569A. To evaluate the MAX8569A, remove the 0Ω
resistor from R5/R11 and the 100kΩ resistor from
R6/R12. Install a 100kΩ resistor at R4/R10. Calculate
R3/R9 (R
where V
1.228V.
Note: The external components may need to be opti-
mized for the selected output voltage, as described in
the MAX8569A/MAX8569B IC data sheet.
OUT
OFF
T
) as follows:
is the battery voltage at which the part
is the desired output voltage and V
R
R
T
T
SHDN
=
T
=
10
) as follows:
10
Evaluating the MAX8569A
6
5
= 1.228V.
×
×
⎛
⎜
⎝
⎛
⎜
⎝
V
V
V
Normal operation
Shutdown mode
SHDN
V
OUT
OFF
OPERATION
FB
−
−
1
1
⎞
⎟
⎠
⎞
⎟
⎠
FB
is
3