Datasheet
DRVH2
VIN
VREG3
EN2
DRVH1
V5SW
RF
EN1
PGOOD2
SKIPSEL2
CSP2
CSN2
PGOOD1
SKIPSEL1
CSP1
CSN1
VFB1
SW1
VBST1
DRVL1
VREG5
GND
DRVL2
VBST2
SW2
COMP1
FUNC
EN
VREF2
TRIP
COMP2
VFB2
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
TPS51220A
RSNPACKAGE
(TOP VIEW)
DRVH2
VIN
VREG3
EN2
DRVH1
V5SW
RF
EN1
PGOOD2
SKIPSEL2
CSP2
CSN2
PGOOD1
SKIPSEL1
CSP1
CSN1
VFB1
SW1
VBST1
DRVL1
VREG5
GND
DRVL2
VBST2
SW2
COMP1
FUNC
EN
VREF2
TRIP
COMP2
VFB2
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
TPS51220A
RTVPACKAGE
(TOP VIEW)
TPS51220A
SLUS897E –DECEMBER 2008–REVISED JANUARY 2013
www.ti.com
DEVICE INFORMATION
PIN FUNCTIONS
PIN
I/O DESCRIPTION
NAME NO.
DRVH1 1
High-side MOSFET gate driver outputs. Source 1.7 Ω, sink 1.0 Ω, SW-node referenced floating driver. Drive
O
voltage corresponds to VBST to SW voltage.
DRVH2 24
SW2 25
I/O High-side MOSFET gate driver returns.
SW1 32
Always alive 3.3 V, 10 mA low dropout linear regulator output. Bypass to (signal) GND with more than 1-μF
VREG3 22 O
ceramic capacitance. Runs from VIN supply or from VREG5 when it is switched over to V5SW input.
EN1 4
Channel 1 and channel 2 SMPS Enable Pins. When turning on, apply greater than 0.55 V and less than 6 V,
I
or leave floating. Connect to GND to disable. Adjustable soft-start capacitance to be attached here.
EN2 21
PGOOD1 5
Powergood window comparator outputs for channel 1 and channel 2. The recommended applied voltage
O
should be less than 6 V, and the recommended pull-up resistance value is from 100 kΩ to 1 MΩ.
PGOOD2 20
SKIPSEL1 6 Skip mode selection pin.
GND: Continuous conduction mode
I
VREF2: Auto Skip
SKIPSEL2 19
VREG3: OOA Auto Skip, maximum 7 skips (suitable for f
sw
< 400kHz)
VREG5: OOA Auto Skip, maximum 15 skips (suitable for equal to or greater than 400kHz)
CSP1 7 Current sense comparator inputs (+). An RC network with high quality X5R or X7R ceramic capacitor should
I/O be used to extract voltage drop across DCR. 0.1-μF is a good value to start the design. See the current
CSP2 18
sensing scheme section for more details.
CSN1 8
Current sense comparator inputs (–). See the current sensing scheme section. Used as power supply for the
I
current sense circuit for 5V or higher output voltage setting. Also, used for output discharge terminal.
CSN2 17
VFB1 9
SMPS voltage feedback Inputs. Connect the feedback resistors divider, and should be referred to (signal)
I
GND.
VFB2 16
COMP1 10 Loop compensation pin for current mode (error amplifier output). Connect R (and C if required) from this pin
to VREF2 for proper loop compensation with current mode operation. Ramp compensation adjustable pin for
I
D-CAP mode, connect R from this pin to VREF2. 10 kΩ is a good value to start the design. 6 kΩ to 20 kΩ
COMP2 15
can be chosen. See the D-CAP MODE section for more details.
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