zl2106 Intersil Corporation, zl2106 Datasheet - Page 17

• Manufacturer Part Number: zl2106
• Description: 6a Digital-dc Synchronous Step-down Dc-dc Converter
• Manufacturer: Intersil Corporation

The soft-start delay period begins when the EN pin is
asserted and ends when the delay time expires. The
soft-start delay period is set using the SS pin. Precise
ramp delay timing mode reduces the delay time
variations and is available when the appropriate bit in
the MISC_CONFIG register had been set. Please refer
to Application Note AN33 for details.
The soft-start ramp timer enables a precisely controlled
ramp to the nominal V
delay period has expired. The ramp-up is guaranteed
monotonic and its slope may be precisely set using the
SS pin. Using the pin-strap method, the soft start delay
and ramp times can be set to one of three standard
values according to Table 9.
Table 9. Soft Start Delay and Ramp Settings
If the desired soft start delay and ramp times are not
one of the values listed in Table 9, the times can be set
to a custom value by connecting a resistor from the SS
pin to SGND using the appropriate resistor value from
Table 10
start-up or Restore and will not change if the resistor is
varied after power has been applied to the ZL2106 (see
Figure 14).
Setting
SS Pin
OPEN
HIGH
LOW
Figure 14. SS Pin Resistor Connections
. The value of this resistor is measured upon
17
Ramp Time
Delay and
OUT
10 ms
2 ms
5 ms
value that begins once the
UVLO
4.5 V
ZL2106
Table 10. Delay and Ramp Configuration
The soft start delay and ramp times can also be set to
custom values via the I
SS delay time is set to 0 ms, the device will begin its
ramp-up after the internal circuitry has initialized
(approx. 2 ms). When the soft-start ramp period is set
to 0 ms, the output will ramp up as quickly as the
output load capacitance and loop settings will allow. It
is generally recommended to set the soft-start ramp to a
value greater than 500 μs to prevent inadvertent fault
conditions due to excessive inrush current.
12.1 kΩ
13.3 kΩ
14.7 kΩ
16.2 kΩ
17.8 kΩ
19.6 kΩ
21.5 kΩ
23.7 kΩ
26.1 kΩ
28.7 kΩ
31.6 kΩ
34.8 kΩ
38.3 kΩ
42.2 kΩ
46.4 kΩ
51.1 kΩ
56.2 kΩ
61.9 kΩ
68.1 kΩ
82.5 kΩ
90.9 kΩ
100 kΩ
110 kΩ
121 kΩ
133 kΩ
147 kΩ
162 kΩ
178 kΩ
10 kΩ
11 kΩ
75 kΩ
R
SS
Delay
10ms
20ms
10ms
20ms
Time
2ms
5ms
2ms
5ms
2
C/SMBus interface. When the
Data Sheet Revision 2/19/2009
Ramp
10ms
10ms
20ms
10ms
20ms
10ms
20ms
10ms
20ms
10ms
20ms
10ms
20ms
10ms
20ms
Time
2ms
5ms
2ms
5ms
2ms
5ms
2ms
5ms
2ms
5ms
2ms
5ms
2ms
5ms
2ms
5ms
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10.8 V
UVLO
4.5 V