L6910G STMicroelectronics, L6910G Datasheet - Page 10
L6910G
Manufacturer Part Number
L6910G
Description
IC PWM BUCK BST VM 16SOICN
Manufacturer
STMicroelectronics
Datasheet
1.L6910GTR.pdf
(26 pages)
Specifications of L6910G
Pwm Type
Voltage Mode
Number Of Outputs
1
Frequency - Max
230kHz
Duty Cycle
100%
Voltage - Supply
5 V ~ 12 V
Buck
Yes
Boost
Yes
Flyback
No
Inverting
No
Doubler
No
Divider
No
Cuk
No
Isolated
No
Operating Temperature
-40°C ~ 150°C
Package / Case
16-SOIC (3.9mm Width)
Frequency-max
230kHz
Topology
Step Down
Output Voltage
0.9 V to 12 V
Output Current
1300 mA
Switching Frequency
50 KHz to 1000 KHz
Duty Cycle (max)
100 %
Maximum Operating Temperature
+ 150 C
Minimum Operating Temperature
- 40 C
Mounting Style
SMD/SMT
Synchronous Pin
No
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
L6910G
Manufacturer:
ST
Quantity:
20 000
Part Number:
L6910GTR
Manufacturer:
ST
Quantity:
20 000
L6910G
Figure 10. Compensation Network
The compensation network consists in the internal error amplifier and the impedance networks Z
C20) and Z
the highest 0dB crossing frequency to have fast response (but always lower than fsw/10) and the highest gain
in DC conditions to minimize the load regulation.
A stable control loop has a gain crossing with -20dB/decade slope and a phase margin greater than 45°. Include
worst-case component variations when determining phase margin.
To locate poles and zeroes of the compensation networks, the following suggestions may be used:
Modulator singularity frequencies:
Compensation network singularity frequency:
10/26
– Put the gain R5/R3 in order to obtain the desired converter bandwidth;
– Place ω
– Place ω
– Place ω
– Place ω
– Check the loop gain considering the error amplifier open loop gain.
FB
Z1
Z2
P1
P2
(R5, C18 and C19). The compensation network has to provide a closed loop transfer function with
before the output filter resonance ω
at the output filter resonance ω
at the output capacitor ESR zero ω
at one half of the switching frequency;
ω
ω
Z1
P1
ω
LC
=
=
∆V
=
----------------------- -
R5 C19
---------------------------------------------- -
R5
OSC
-------------------------- -
⋅
1
L C
⋅
COMPARATOR
⋅
---------------------------- -
C18
C18 C19
1
PWM
OUT
1
+
⋅
V
COMP
C19
LC
R5
;
C18
ESR
LC
;
;
C19
+
ω
ω
-
EAREF
ESR
Z2
V
IN
=
C20
=
ω
L
------------------------------------------ -
(
C
P2
R3
OUT
D03IN1512
ESR
-------------------------------- -
ESR C
R3
R4
=
+
V
R4
----------------------- -
R4 C20
⋅
OUT
1
1
) C20
OUT
⋅
1
⋅
IN
(R3, R4 and