16
FN6849.3
December 16, 2011
The standard method for adjusting output voltage used
in a POLA module is defined by the below equation:
R
set
= 10kΩ x 0.69V/(V
OUT
– 0.69V) – 1.43kΩ
Rset is an external resistor.
VADJ
ZL2005P
10
kOhm
MODULE
R
SET
-
+
1.43
kOhm
R
SET
0.69V
10
kOhm
V
OUT
POLA Module
Figure 11. Output Voltage Resistor Setting
POLA - ZL2005P
To stay compatible with existing methods for
adjusting
output voltage, the module manufacturer can add a 10
kΩ resistor on the module.
R
VADJ
= R
SET
+10 kΩ
By adding this additional resistor
, the resistor values
shown in Table 8 can be used to set the output
voltage
of a ZL2005P module. These values are close to the
a
nalog POLA values and are compatible with the pin-
strap resistor detection methodology of the ZL2005P.
DOSA Voltage Trim Method
For DOSA output voltage selection, a 8.66 kΩ re
sistor
needs to be used in place of the 10 kΩ
resistor. This
will allow setting the output voltage with resistor val-
ues close to the DOSA equation result:
R
set
= 6900/(V
OUT
– 0.69V).
Table 9. Resistors for Setting DOSA Output
V
oltage with VADJ
0.700V 156 / 160 / 170 0.991V 22.71 / 22.94 / 23.17
0.752V 111.22 / 112.34 / 113.46 1.000V 19.84 / 20.04 / 20.24
0.758V 100.33 / 101.34 / 102.35 1.100V 17.27 / 17.44 / 17.61
0.765V 90.43 / 91.34 / 92.25 1.158V 14.89 / 15.04 / 15.19
0.772V 81.42 / 82.24 / 83.06 1.200V 12.71 / 12.84 / 12.97
0.790V 65.68 / 73.84 / 74.58 1.250V 10.83 / 10.94 / 11.05
0.800V 58.85 / 59.44 / 60.03 1.500V 9.05 / 9.14 / 9.23
0.821V 52.71 / 53.24 / 53.77 1.669V 7.46 / 7.54 / 7.62
0.848V 42.02 / 42.44 / 42.86 1.800V 5.98 / 6.04 / 6.10
0.880V 37.36 / 37.74 / 38.12 2.295V 4.59 / 4.64 / 4.69
0.899V 33.20 / 33.54 / 33.88 2.506V 3.41 / 3.44 / 3.47
0.919V 29.34 / 29.64 / 29.94 3.300V 2.32 / 2.34 / 2.36
0.965V 25.88 / 26.14 / 26.40 5.000V 1.33 / 1.34 / 1.35
UVLO (POLA Mode)
In POLA mode 1 and 2, undervoltage threshold
(UVLO)
is set following POLA standard methodol-
ogy.
In the POLA standard, a resistor on the UVLO pin sets
the corresponding voltage value.
For a module supplier, a 1.5 kΩ 1% pull-up resistor
from EN to UVLO is required to be compatible with
the POLA Inhibit/UVLO features (Figure 12). EN
must be driven by an open
collector/drain driver, and
will default to Enabled unless pulled low. The driver
must remain open after a transition for a minimum of 1
ms to allow the measurement of the resistor on the
UVLO pin.
By default UVLO is set to 4.5V.
Table 8. Resistors for Setting POLA Output
V
oltage with VADJ
V
OUT
R
SET
(kΩ)
Min / Typ / Max
V
OUT
R
SET
(kΩ)
Min / Typ / Max
0.700V 155 / 159 / 169 0.991V 21.38 / 21.6 / 21.82
0.752V 109.89 / 111 / 112.11 1.000V 18.51 / 18.7 / 18.89
0.758V 99 / 100 / 101 1.100V 15.94 / 16.1 / 16.26
0.765V 89.1 / 90 / 90.9 1.158V 13.56 / 13.7 / 13.84
0.772V 80.09 / 80.9 / 81.71 1.200V 11.39 / 11.5 / 11.62
0.790V 64.35 / 72.5 / 73.23 1.250V 9.5 / 9.6 / 9.7
0.800V 57.52 / 58.1 / 58.68 1.500V 7.72 / 7.8 / 7.88
0.821V 51.38 / 51.9 / 52.42 1.669V 6.14 / 6.2 / 6.26
0.848V 40.69 / 41.1 / 41.51 1.800V 4.65 / 4.7 / 4.75
0.880V 36.04 / 36.4 / 36.76 2.295V 3.27 / 3.3 / 3.33
0.899V 31.88 / 32.2 / 32.52 2.506V 2.08 / 2.1 / 2.12
0.919V 28.02 / 28.3 / 28.58 3.300V 0.99 / 1 / 1.01
0.965V 24.55 / 24.8 / 25.05 5.000V 0 / 0 / 0.05
V
OUT
R
SET
(kΩ)
Min / Typ / Max
V
OUT
R
SET
(kΩ)
Min / Typ / Max
ZL2005P