Datasheet

LMZ30606
www.ti.com SNVS995 –JULY 2013
APPLICATION INFORMATION
ADJUSTING THE OUTPUT VOLTAGE
The VADJ control sets the output voltage of the LMZ30606. The output voltage adjustment range is from 0.8V to
3.6V. The adjustment method requires the addition of R
SET
, which sets the output voltage, the connection of
SENSE+ to VOUT, and in some cases R
RT
which sets the switching frequency. The R
SET
resistor must be
connected directly between the VADJ (pin 35) and AGND (pin 33 & 34). The SENSE+ pin (pin 36) must be
connected to VOUT either at the load for improved regulation or at VOUT of the module. The R
RT
resistor must
be connected directly between the RT/CLK (pin 4) and AGND (pins 33 & 34).
Table 1 gives the standard external R
SET
resistor for a number of common bus voltages, along with the
recommended R
RT
resistor for that output voltage.
Table 1. Standard R
SET
Resistor Values for Common Output Voltages
RESISTORS OUTPUT VOLTAGE V
OUT
(V)
0.8 1.2 1.5 1.8 2.5 3.3
R
SET
(kΩ) open 2.87 1.65 1.15 0.673 0.459
R
RT
(kΩ) 1200 715 348 348 348 348
For other output voltages, the value of the required resistor can either be calculated using the following formula,
or simply selected from the range of values given in Table 2.
(1)
Table 2. Standard R
SET
Resistor Values
V
OUT
(V) R
SET
(kΩ) R
RT
(kΩ) f
SW
(kHz) V
OUT
(V) R
SET
(kΩ) R
RT
(kΩ) f
SW
(kHz)
0.8 open 1200 650 2.3 0.768 348 1000
0.9 11.8 1200 650 2.4 0.715 348 1000
1.0 5.83 1200 650 2.5 0.673 348 1000
1.1 3.83 1200 650 2.6 0.634 348 1000
1.2 2.87 715 750 2.7 0.604 348 1000
1.3 2.32 715 750 2.8 0.576 348 1000
1.4 1.91 715 750 2.9 0.549 348 1000
1.5 1.65 348 1000 3.0 0.523 348 1000
1.6 1.43 348 1000 3.1 0.499 348 1000
1.7 1.27 348 1000 3.2 0.475 348 1000
1.8 1.15 348 1000 3.3 0.459 348 1000
1.9 1.05 348 1000 3.4 0.442 348 1000
2.0 0.953 348 1000 3.5 0.422 348 1000
2.1 0.845 348 1000 3.6 0.412 348 1000
2.2 0.825 348 1000
Copyright © 2013, Texas Instruments Incorporated Submit Documentation Feedback 9
Product Folder Links: LMZ30606