lb1955 Sanyo Semiconductor Corporation, lb1955 Datasheet - Page 5

• Manufacturer Part Number: lb1955
• Description: Three-phase Brushless Motor Driver
• Manufacturer: Sanyo Semiconductor Corporation

VG and LIM Pin Usage
Note: This current limiting function is for protection against unusual and abnormal currents. If a current limit level below the rated current is set, this will,
PG and FG Pin Output Circuits
When the LIM pin is open, VG is shorted to Rf, and Rf = 0.47 , this will result in a current limit level of about 1.3 to 1.4 A. If this limit falls under the
inversely, result in heat generation within the IC.
rated value due to mode changes or changes in the value of the Rf resistor, set the current limit to an appropriate value by applying to the LIM pin a
voltage that is divided from the V
function.
REF
to ground potential by resistors of a few k . Alternatively, short the LIM pin to V
Output
stage
LB1955
FG (FGR shorted to ground)
PG (FGR shorted to PG)
LIM pin: Open
LIM – V
VG pin: Open
VG – Rf: Shorted
Gm = 0.423/Rf (A/V)
Ilim = (V
Gm = 1/Rf (A/V)
Ilim = (V
No current limit.
REF
: Shorted
(Closed loop control gain)
(Current limit)
(Closed loop control gain)
(Current limit)
REF
REF
27/200 – 0.2) 10/3/Rf
27/200 – 0.2)
REF
4.23/3/Rf
to defeat the current limit
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