SP6652ER-L Exar Corporation, SP6652ER-L Datasheet - Page 10

• Manufacturer Part Number: SP6652ER-L
• Description: IC PWM BUCK CURRENT MODE 10DFN
• Manufacturer: Exar Corporation
• Type: Step-Down (Buck)r

Specifications of SP6652ER-L

• Package / Case: 10-VFDFN Exposed Pad
• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.9 V ~ 5 V
• Current - Output: 1A
• Frequency - Switching: 1.4MHz
• Voltage - Input: 2.85 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: *
• Output Voltage: Adjustable
• Output Current: 1 A
• Input Voltage: 2.85 V to 5.5 V
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1216

Oct10-07 RevJ
over frequency f
Bode plot) divided by the loop gain band-
width, given as 20kHz, which is used in the
following equation:
Error Amp Gain
= f
= 80kHz / 20kHz
= 4
The error amp transconductance is about
1mS, so this sets the R
Rz = 4/1mS = 4KΩ
We will use R
compensation.
zero
/ (loop gain bandwidth)
Figure 4. Typical SP6652 circuit layout.
Z
= 4KΩ for the 3.3V output
zero
= 80kHz (from the
SP6652 1A, High Efficiency, Current Mode PWM Buck Regulator
Z
resistor to be:
0
The zero for loop compensation is placed
at the first modulator pole of 4 kHz to pro-
vide a loop response of -20/dB/decade at
the crossover frequency. The compensa-
tion capacitor Cc can be calculated from
the crossover frequency pole1 and the R
value:
C
= 10nF
From the Typical Performance Charac-
teristics load step curves, the 2.5V output
and 3.3V output are stable with R
and C
the values R
recommended.
C
= 1/(2π• R
C
= 10nF. For 1.8V to 0.85V output,
APPLICATIONS INFORMATION
Z
Z
= 2KΩ and C
•pole1) = 1/(2π•4K•4kHz)
© 2007 Sipex Corporation
C
= 10nF are
Z
= 4KΩ
Z