Cherry Semiconductor CS5155GN16, CS5155GDR16, CS5155GD16 Datasheet
The CS5155 is a 5-bit synchronous
dual N-Channel buck controller. It
is designed to provide unprecedented transient response for
todayÕs demanding high-density,
high-speed logic. The regulator
operates using a proprietary control
method, which allows a 100ns
response time to load transients.
The CS5155 is designed to operate
over a 4.25-14V range (VCC) using
12V to power the IC and 5V as the
main supply for conversion.
The CS5155 is specifically designed
to power Pentium¨II processors
and other high performance core
logic. It includes the following features: on board, 5-bit DAC, short
circuit protection, 1.0% output tolerance, VCCmonitor, and programmable soft start capability. The
CS5155 is backwards compatible
with the 4 bit CS-5150, allowing the
mother board designer the capability of using either the CS-5150 or the
CS5155 with no change in layout.
The CS5155 is available in 16 pin
surface mount and DIP packages.
Features
■ Dual N-Channel Design
■ Excess of 1MHz Operation
■ 100ns Transient Response
■ 5-Bit DAC
■ Backward Compatible with
4 Bit CS-5150/5151 and
Adjustable CS-5120/5121
■ 30ns Gate Rise/Fall Times
■ 1% DAC Accuracy
■ 5V & 12V Operation
■ Remote Sense
■ Programmable Soft Start
■ Lossless Short Circuit
Protection
■ V
CC
Monitor
■ 25ns FET Nonoverlap Time
■ Adaptive Voltage
Positioning
■ V
2
ª
Control Topology
■ Current Sharing
■ Overvoltage Protection
Package Options
CPU 5-Bit Synchronous Buck Controller
CS5155
Description
Application Diagram
V
ID0
V
ID1
V
ID2
V
ID3
SS
V
ID4
C
OFF
V
FFB
V
FB
COMP
LGnd
V
CC1
V
GATE(L)
PGnd
V
GATE(H)
V
CC2
16 Lead SO Narrow & PDIP
1
Switching Power Supply for core logic - Pentium¨II processor
0.33mF
V
ID0
V
ID1
V
ID2
V
ID3
V
ID0
V
ID1
V
ID2
V
ID3
V
CC1
SS
CS5155
C
OFF
LGnd
V
FB
V
FFB
COMP
IRL3103
IRL3103
0.1mF
12V 5V
2mH
1.3V to 3.5V @ 13A
V
CC2
V
GATE(H)
V
GATE(L)
PGnd
1200mF/16V x 3
AlEl
3.3k
0.1mF
1200mF/16V x 5
AlEl
100pF
330pF
V
ID4
V
ID4
V2is a trademark of Switch Power, Inc.
Pentium is a registered trademark of Intel Corporation.
CS5155
Rev. 1/22/99
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
A Company
¨
1
2
Pin Name Max Operating Voltage Max Current
V
CC1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25mA DC/1.5A peak
V
CC2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20mA DC/1.5A peak
SS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-100µA
COMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200µA
VFB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA
C
OFF
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA
V
FFB
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2µA
V
ID0
- V
ID4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-50µA
V
GATE(H)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mA DC/1.5A peak
V
GATE(L)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V/-0.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mA DC/1.5A peak
LGnd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25mA
PGnd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100mA DC/1.5A peak
Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0¡ to 150¡C
Lead Temperature Soldering
Wave Solder (through hole styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 sec. max, 260¡C peak
Reflow (SMD styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 sec. max above 183¡C, 230¡C peak
Storage Temperature Range, TS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65¡ to 150¡C
ESD Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
CS5155
Electrical Characteristics: 0¡C < TA< +70¡C; 0¡C < TJ< +85¡C; 8V < V
CC1
< 14V; 5V < V
CC2
< 20V;
DAC Code: V
ID4
= V
ID2
= V
ID1
= V
ID0
= 1; V
ID3
= 0; CV
GATE(L)
and CV
GATE(H)
= 1nF; C
OFF
= 330pF; CSS= 0.1µF, unless otherwise specified.
Absolute Maximum Ratings
■ Error Amplifier
VFBBias Current VFB= 0V 0.3 1.0 µA
Open Loop Gain 1.25V < V
COMP
< 4V; Note 1 50 60 dB
Unity Gain Bandwidth Note 1 500 3000 kH
COMP SINK Current V
COMP
= 1.5V; VFB= 3V; VSS> 2V 0.4 2.5 8.0 mA
COMP SOURCE Current V
COMP
= 1.2V; VFB= 2.7V; VSS= 5V 30 50 70 µA
COMP CLAMP Current V
COMP
= 0V; VFB= 2.7V 0.4 1.0 1.6 mA
COMP High Voltage VFB= 2.7V; VSS= 5V 4.0 4.3 5.0 V
COMP Low Voltage VFB=3V 160 300 mV
PSRR 8V < V
CC1
< 14V @ 1kHz; Note 1 60 85 dB
■ V
CC1
Monitor
Start Threshold Output switching 3.75 3.90 4.05 V
Stop Threshold Output not switching 3.70 3.85 4.00 V
Hysteresis Start-Stop 50 mV
■ DAC
Input Threshold V
ID0
, V
ID1
, V
ID2
, V
ID3
, V
ID4
1.00 1.25 2.40 V
Input Pull Up Resistance V
ID0
, V
ID1
, V
ID2
, V
ID3
, V
ID4
25 50 100 k½
Pull Up Voltage 4.85 5.00 5.15 V
Accuracy Measure VFB= V
COMP
, 25¡C ² TJ² 85¡C 1.0 %
V
ID4VID3VID2VID1VID0
01111 1.3266 1.3400 1.3534 V
01110 1.3761 1.3900 1.4039 V
01101 1.4256 1.4400 1.4544 V
0 1 1 0 0 1.4751 1.4900 1.5049 V
CS5155
3
Electrical Characteristics: 0¡C < TA< +70¡C; 0¡C < TJ< +85¡C; 8V < V
CC1
< 14V; 5V < V
CC2
< 20V;
DAC Code: V
ID4
= V
ID2
= V
ID1
= V
ID0
= 1; V
ID3
= 0; CV
GATE(L)
and CV
GATE(H)
= 1nF; C
OFF
= 330pF; CSS= 0.1µF, unless otherwise specified.
■ DAC: continued
V
ID4VID3VID2VID1VID0
01011 1.5246 1.5400 1.5554 V
01010 1.5741 1.5900 1.6059 V
01001 1.6236 1.6400 1.6564 V
0 1 0 0 0 1.6731 1.6900 1.7069 V
0 0 1 1 1 1.7226 1.7400 1.7574 V
0 0 1 1 0 1.7721 1.7900 1.8079 V
0 0 1 0 1 1.8216 1.8400 1.8584 V
0 0 1 0 0 1.8711 1.8900 1.9089 V
00011 1.9206 1.9400 1.9594 V
00010 1.9701 1.9900 2.0099 V
00001 2.0196 2.0400 2.0604 V
0 0 0 0 0 2.0691 2.0900 2.1109 V
11111 1.2315 1.2440 1.2564 V
11110 2.1186 2.1400 2.1614 V
11101 2.2176 2.2400 2.2624 V
11100 2.3166 2.3400 2.3634 V
11011 2.4156 2.4400 2.4644 V
11010 2.5146 2.5400 2.5654 V
11001 2.6136 2.6400 2.6664 V
11000 2.7126 2.7400 2.7674 V
10111 2.8116 2.8400 2.8684 V
10110 2.9106 2.9400 2.9694 V
10101 3.0096 3.0400 3.0704 V
10100 3.1086 3.1400 3.1714 V
10011 3.2076 3.2400 3.2724 V
10010 3.3066 3.3400 3.3734 V
10001 3.4056 3.4400 3.4744 V
10000 3.5046 3.5400 3.5754 V
■ V
GATE(H)
and V
GATE(L)
Out SOURCE Sat at 100mA Measure V
CC1
Ð V
GATE(L),;VCC2
Ð V
GATE(H)
1.2 2.0 V
Out SINK Sat at 100mA Measure V
GATE(H)
Ð VPGnd; 1.0 1.5 V
V
GATE(L)
Ð VPGnd
Out Rise Time 1V < V
GATE(H)
< 9V; 1V < V
GATE(L)
< 9V 30 50 ns
V
CC1
= V
CC2
= 12V
Out Fall Time 9V > V
GATE(H)
> 1V; 9V > V
GATE(L)
> 1V 30 50 ns
V
CC1
= V
CC2
= 12V
Shoot-Through Current Note 1 50 mA
Delay V
GATE(H)
to V
GATE(L)
V
GATE(H)
falling to 2V; V
CC1
= V
CC2
= 8V 25 50 ns
V
GATE(L)
rising to 2V
Delay V
GATE(L)
to V
GATE(H)
V
GATE(L)
falling to 2V; V
CC1
= V
CC2
= 8V 25 50 ns
V
GATE(H)
rising to 2V
V
GATE(H)
, V
GATE(L)
Resistance Resistor to LGnd 20 50 100 k½
V
GATE(H)
, V
GATE(L)
Schottky LGnd to V
GATE(H)
@ 10mA 600 800 mV
LGnd to V
GATE(L)
@ 10mA
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
4
CS5155
Package Pin Description
PACKAGE PIN # PIN SYMBOL FUNCTION
16L SO Narrow & PDIP
1,2,3,4,6 V
ID0
Ð V
ID4
Voltage ID DAC input pins. These pins are internally pulled up to 5V
providing logic ones if left open. V
ID4
selects the DAC range. When V
ID4
is High (logic one), the DAC range is 2.14V to 3.54V with 100mV increments. When V
ID4
is Low (logic zero), the DAC range is 1.34V to 2.09V
with 50mV increments. V
ID0
- V
ID4
select the desired DAC output voltage. Leaving all 5 DAC input pins open results in a DAC output voltage
of 1.244V, allowing for adjustable output voltage, using a traditional
resistor divider.
5 SS Soft Start Pin. A capacitor from this pin to LGnd in conjunction with
internal 60µA current source provides soft start function for the controller. This pin disables fault detect function during Soft Start. When a
fault is detected, the soft start capacitor is slowly discharged by internal
2µA current source setting the time out before trying to restart the IC.
Charge/discharge current ratio of 30 sets the duty cycle for the IC when
the regulator output is shorted.
■ Soft Start (SS)
Charge Time 1.6 3.3 5.0 ms
Pulse Period 25 100 200 ms
Duty Cycle (Charge Time/Pulse Period) ´ 100 1.0 3.3 6.0 %
COMP Clamp Voltage V
FB
= 0V; VSS= 0 0.50 0.95 1.10 V
V
FFB
SS Fault Disable V
GATE(H)
= Low; V
GATE(L)
= Low 0.9 1.0 1.1 V
High Threshold 2.5 3.0 V
■ PWM Comparator
Transient Response V
FFB
= 0 to 5V to V
GATE(H)
= 9V to 1V; 100 125 ns
V
CC1
= V
CC2
= 12V
V
FFB
Bias Current V
FFB
= 0V 0.3 µA
■ Supply Current
I
CC1
No Switching 8.5 13.5 mA
I
CC2
No Switching 1.6 3.0 mA
Operating I
CC1
VFB= COMP = V
FFB
813mA
Operating I
CC2
VFB= COMP = V
FFB
25mA
■ C
OFF
Normal Charge Time V
FFB
= 1.5V; VSS= 5V 1.0 1.6 2.2 µs
Extension Charge Time VSS= V
FFB
= 0 5.0 8.0 11.0 µs
Discharge Current C
OFF
to 5V; V
FB
>1V 5.0 mA
■ Time Out Timer
Time Out Time VFB= V
COMP
; V
FFB
= 2V; 10 30 50 µs
Record V
GATE(H)
Pulse High Duration
Fault Mode Duty Cycle V
FFB
= 0V 35 50 65 %
Note 1: Guaranteed by design, not 100% tested in production.
Electrical Characteristics: 0¡C < TA< +70¡C; 0¡C < TJ< +85¡C; 8V < V
CC1
< 14V; 5V < V
CC2
< 20V;
DAC Code: V
ID4
= V
ID2
= V
ID1
= V
ID0
= 1; V
ID3
= 0; CV
GATE(L)
and CV
GATE(H)
= 1nF; C
OFF
= 330pF; CSS= 0.1µF, unless otherwise specified.
5
CS5155
Block Diagram
Package Pin Description: continued
PACKAGE PIN # PIN SYMBOL FUNCTION
16L SO Narrow & PDIP
7C
OFF
A capacitor from this pin to ground sets the time duration for the on
board one shot, which is used for the constant off time architecture.
8V
FFB
Fast feedback connection to the PWM comparator. This pin is connected to the regulator output. The inner feedback loop terminates on time.
9V
CC2
Boosted power for the high side gate driver.
10 V
GATE(H)
High FET driver pin capable of 1.5A peak switching current. Internal
circuit prevents V
GATE(H)
and V
GATE(L)
from being in high state simul-
taneously.
11 PGnd High current ground for the IC. The MOSFET drivers are referenced to
this pin. Input capacitor ground and the source of lower FET should be
tied to this pin.
12 V
GATE(L)
Low FET driver pin capable of 1.5A peak switching current.
13 V
CC1
Input power for the IC and low side gate driver.
14 LGnd Signal ground for the IC. All control circuits are referenced to this pin.
15 COMP Error amplifier compensation pin. A capacitor to ground should be
provided externally to compensate the amplifier.
16 V
FB
Error amplifier DC feedback input. This is the master voltage feedback
which sets the output voltage. This pin can be connected directly to the
output or a remote sense trace.
V
CC1
SS
V
ID0
V
ID1
V
ID2
V
ID3
V
ID4
V
COMP
V
FFB
LGnd
V
V
Monitor
CC1
Comparator
-
60mA
2mA
-
+
-
+
V
FFB
Comparator
5V
2.5V
Low
+
3.90V
3.85V
5 BIT
DAC
FB
Slow Feedback
Fast Feedback
Error
Amplifier
+
PWM
Comparator
1V
0.7V
-
+
+
-
Maximum
On-Time
Timeout
Normal
Off-Time
Timeout
Extended
Off-Time
Timeout
SS Low
Comparator
SS High
Comparator
R
S
FAULT
Latch
Off-Time
Timeout
FAULT
Q
FAULT
Q
GATE(H) = ON
Q
R
Q
GATE(H) = OFF
C
OFF
One Shot
R
S
Q
S
PWM
Latch
PGnd
V
CC1
CC2
V
GATE(H)
V
GATE(L)
PGnd
C
OFF
PWM
COMP
Time Out
Timer
(30ms)
Edge Triggered
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