TS3300 Demo Board
FB) pin is 505mV. It is recommended to use large
resistor values to minimize additional current draw at
the output. Resistors values less than 8MΩ are
recommended. Boost output voltage can be set by
solving for R3 for a given R6 value in the following
equation:
DESCRIPTION
The TS3300 boost regulator is set to an output
voltage of 3V while the LDO is set to an output
voltage of 1.8V via a resistor divider circuit. The boost
regulator and the LDO can be shutdown separately
via J1 and the combination of J2 and J3, respectively.
The LDO switch/FET can be fully enhanced via the
combination of J2 and J3. Refer to Table 1 and Table
2. The complete demo board circuit is shown in
Figure 6.
ꢀ
ꢂꢃO ꢄ 0.505 ꢀ6
ꢀ3ꢁ
0.505
To set a 3V output voltage with R6 = 1.37MΩ, R3 is
calculated to be 6.77MΩ. A 1% standard resistor
value of 6.81MΩ is selected. This results in an output
voltage of 3.02V.
Resistor R1 in combination with R2 create a voltage
divider circuit that sets the desired anti-crushTM
voltage. The demo board does not include R2. Refer
to the TS3300 product datasheet “Applications
Information” section for more details.
LDO OUTPUT VOLTAGE SETTING
The LDO output voltage can be set independently of
the boost, via a voltage divider circuit as shown in
Figure 4.
SW EN
REG EN
Jumper Jumper
CONDITION
FUNCTION
J2
J3
REG FB
connected to
R4, R5
LDO Normal
Operation
REG FB
connected to BO
low
high
LDO
Shutdown
pin
(See “Quick Start
Procedure”, step 6)
Figure 4: Setting the LDO Output Voltage
with a Voltage Divider
Internal FET
Hard-on
high
low
Table 1. LDO REG EN(J3) and SW EN(J2)Settings
The output feedback (REG FB) pin is 505mV. It is
recommended to use large resistor values to
minimize additional current drawn from the output.
The LDO output voltage can be set by solving for R4
for a given R5 value in the following equation:
ꢁꢁꢁꢁꢁꢁꢁ
ꢀꢁ
Jumper
J1
FUNCTION
ꢀ
ꢂꢀꢆꢇOꢈT ꢄ 0.505 ꢀ5
low
Boost Enabled
ꢀꢅꢁ
0.505
high
Boost Shutdown
Table 2. Boost Regulator Shutdown/Enable Settings
To set a 1.8V output voltage with R4 = 2.61MΩ, R4 is
calculated to be 6.69MΩ. A 1% standard resistor
value of 6.81MΩ is selected. This results in an output
voltage of 1.82V.
BOOST REGULATOR OUTPUT VOLTAGE
SETTING
ANTI-CRUSHTM VOLTAGE SETTING
The output voltage can be set via a voltage divider
circuit as shown in Figure 3. The output feedback (BO
To set the anti-crushTM voltage, a feedback pin (BI
FB) in conjunction with a voltage divider circuit can be
implemented as shown in Figure 5. The feedback pin
voltage is 392mV. It is recommended to use large
resistor values to minimize additional current draw at
the input.
Figure 3: Setting the Boost Output Voltage
with a Voltage Divider
TS3300DB r1p0
Page 2
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