zl2006 Intersil Corporation, zl2006 Datasheet - Page 25

• Manufacturer Part Number: zl2006
• Description: Adaptive Digital Dc-dc Controller With Drivers And Current Sharing
• Manufacturer: Intersil Corporation

ILIM0 Pin
Table 19. Resistor Settings for Current Sensing
Notes:
1. 10 kΩ < R
2. The number of violations allowed prior to issuing a fault response.
R
R
R
Figure 17. Current Sensing Methods
ILIM0
ILIM0
ILIM0
1
ILIM0
ILIM1 Pin
Resistor
< 100 kΩ
OPEN
HIGH
LOW
25
Output-referenced, down-slope sensing
Output-referenced, up-slope sensing
Ground-referenced, R
Current Limiting Configuration
(Inductor DCR sensing)
(Inductor DCR sensing)
Blanking time: 672 ns
Blanking time: 352 ns
Blanking time: 352 ns
Depends on resistor value used; see Table 20
ZL2006
DS(ON)
, sensing
The ZL2006 supports “lossless” current sensing by
measuring the voltage across a resistive element that is
already present in the circuit. This eliminates
additional efficiency losses incurred by devices that
must use an additional series resistance in the circuit.
To set the current limit threshold, the user must first
select a current sensing method. The ZL2006
incorporates two methods for current sensing,
synchronous MOSFET R
DC resistance (DCR) sensing; Figure 17 shows a
simplified schematic for each method.
The current sensing method can be selected using the
ILIM1 pin using Table 19. The ILIM0 pin must have a
finite resistor connected to ground in order for Table
19 to be valid. If no resistor is connected between
ILIM0 and ground, the default method is MOSFET
R
modified via the I
Application Note AN33 for details.
In addition to selecting the current sensing method, the
ZL2006 gives the power supply designer several
choices for the fault response during over or under
current condition. The user can select the number of
violations allowed before declaring fault, a blanking
time and the action taken when a fault is detected.
DS(ON)
sensing. The current sensing method can be
Number of
Violations
Allowed
2
5
5
5
C/SMBus interface. Please refer to
2
DS(ON)
Best for high duty cycle
Best for low duty cycle
Best for low duty cycle
sensing and inductor
December 15, 2010
and high f
Comments
and low f
FN6850.1
SW
SW