GAMMA GM6155

Features
Description
GM6155 is an efficient linear voltage regulator with ultralow
Ultra low noise output
- noise output, very low dropout voltage (typically 17mV at
High output voltage accuracy
light loads and 165mV at 50mA), and very low ground cur-
Extremely accurate output voltage
rent (600µA at 100mA output). GM6155 provides better
Guaranteed 150mA output
than 1% initial accuracy.
Low quiescent current
Designed especially for hand-held, battery-powered de-
Low dropout voltage
vices, GM6155 includes a CMOS or TTL compatible en-
Extremely tight load and line regulation
able/ shutdown control input. When shutdown, power con-
Very low temperature coefficient
sumption drops nearly to zero. Regulator ground current in-
Current and thermal limiting
creases only slightly in dropout, further prolonging battery
Reverse-battery protection
life. Key features of GM6155 include a reference bypass
pin to improve its excellent low-noise performance, re-
"Zero" off-mode current
versed-battery protection, current limiting, and over-
Logic-controlled electronic enable
temperature shutdown.
The GM6155 is available in SOT-25 package.
Application
Cellular telephones
Laptop, notebook, and palmtop computers
Battery-powered equipment
PCMCIA VCC and VPP regulation/ switching
Consumer/ personal electronics
SMPS post-regulator/ dc-to-dc modules
High-efficiency linear power supplies
1
2
Enable
Shutdown
3
5
VOUT
COUT = 2.2µF
(tantalum)
4
EN
CBYP
EN (pin 3) may be connected
directly to IN (pin1).
Low-Noise Operation:
CBYP = 470pF, COUT
Basic Operation:
CBYP = not used, COUT
2.2µF
1µF
www.gammamicro.com
GM6155 V0.1
VIN
GM6155-3.3
TYPICAL APPLICATION CIRCUITS
1
MARKING INFORMATION & PIN CONFIGURATIONS (TOP VIEW)
SOT-25 (SOT-23-5)
SOT-25 (SOT-23-5)
OUT
BYP
OUT
ADJ
5
4
5
4
XXVYW
2
1
Part
Identification
XXVYW
3
1
2
3
IN GND EN
IN GND EN
Fixed Voltages
Adjustable Voltage
XX
V
Y
W
= Marking Code(DA = GM6155)
= Voltage Code
= Year
= Weekly
ORDERING INFORMATION
Output Voltage Voltage Code
Ordering Number
Adj
GM6155-AST25R
2.5V
GM6155-2.5ST25R
2.7V
GM6155-2.7ST25R
Package
Shipping
A
SOT-25
3,000 Units/ Tape & Reel
G
SOT-25
3,000 Units/ Tape & Reel
T
SOT-25
3,000 Units/ Tape & Reel
3,000 Units/ Tape & Reel
GM6155-2.8ST25R
2.8V
H
SOT-25
GM6155-2.9ST25R
2.9V
X
SOT-25
3,000 Units/ Tape & Reel
GM6155-3.0ST25R
3.0V
J
SOT-25
3,000 Units/ Tape & Reel
GM6155-3.3ST25R
3.3V
K
SOT-25
3,000 Units/ Tape & Reel
GM6155-3.6ST25R
3.6V
L
SOT-25
3,000 Units/ Tape & Reel
GM6155-4.0ST25R
4.0V
M
SOT-25
3,000 Units/ Tape & Reel
GM6155-4.2ST25R
4.2V
Y
SOT-25
3,000 Units/ Tape & Reel
GM6155-5.0ST25R
5.0V
Q
SOT-25
3,000 Units/ Tape & Reel
* For detail Ordering Number identification, please see last page.
GM6155
PIN DESCRIPTION
2
Function
Pin Number
Pin Name
1
IN
2
GND
3
EN
Enable/ Shutdown(Input): COMS compatible input. Logic high = enable,
logic low or open = shutdown.
4
BYP
Reference Bypass: Connect external 470pF capacitor to GND to reduce
output noise. May be left open.
5
OUT
Regulator Output
Supply Input
Ground
BLOCK DIAGRAM
VIN
VOUT
OUT
IN
+
BYP
CBYP
(Optional)
COUT
+
-
Bandgap
Ref.
VIN
OUT
IN
VOUT
+
COUT
EN
R1
ADJ
Current Limit
Thermal Shutdown
+
R2
-
GND
Bandgap
Ref.
EN
CBYP
(Optional)
VOUT = VREF (1 + R2/ R1)
Figure 1. Ultra-Low-Noise Fixed Regulator
Current Limit
Thermal Shutdown
GND
Figure 2. Ultra-Low-Noise Adjustable Regulator
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
RATINGS
UNITS
Supply Input Voltage
VIN
-20 ~ + 20
V
Enable Input Voltage
VEN
-20 ~ +20
V
Power Dissipation (Note 3)
PD
Internally Limited
W
Junction Temperature
TJ
-40 ~ +125
°C
TLEAD
260
°C
TS
-60 ~ +150
°C
SYMBOL
RATINGS
UNITS
Lead Temperature (soldering, 5 seconds)
Storage Temperature
PARAMETER
Supply Input Voltage
VIN
+2.5 to +16
V
Enable Input Voltage
VEN
0 to VIN
V
Junction Temperature
TJ
-40 ~ + 125
°C
Thermal Resistance
qJA
(Note 3)
°C/ W
GM6155
OPERATING RATINGS
3
ELECTRICAL CHARACTERISTICS
(VIN = VOUT + 1V; IL = 100µA; CL = 1.0µF; VEN
unless otherwise noted)
2.0; TJ = 25°C, bold values indicate -40°C
Typ
TJ
Symbol
Test Condition
Min
VO
Variation from specified VOUT
-1
-2
Output Voltage Temperature
Coefficient
DVO/ DT
(Note 4)
40
Line Regulation
DVO/ VO
VIN = VOUT + 1V to 16V
0.004
0.012/
0.05
%/ V
Load Regulation
DVO/ VO
IL = 0.1mA to 150mA, (Note 5)
0.02
0.2/ 0.5
%
IL = 100µA
10
IL = 50mA
110
IL = 100mA
140
IL = 150mA
165
50
70
150
230
250
300
275
350
1
Parameter
Output Voltage Accuracy
Dropout Voltage (Note 6)
Quiescent Current
Ground Pin Current (Note 7)
VIN - VO
IGND
VEN
0.4V (shutdown)
VEN
0.18V (shutdown)
VEN
2.0V, IL = 0.1mA
IGND
0.01
Max
Unit
1
2
%
ppm/ °C
mV
µA
80
IL = 50mA
350
IL = 100mA
600
IL = 150mA
1300
5
125
150
600
800
1000
1500
1900
2500
µA
Ripple Rejection
PSRR
f = 100Hz, IL = 0.1mA
75
Current Limit
ILIMT
VOUT = 0V
320
(Note 8)
0.05
%/ W
260
nV/ Hz
Thermal Regulation
Output Noise
DVO/ DPD
eNO
+125°C;
IL = 50mA, CL = 2.2µF,
470pF from BYP to GND
dB
500
mA
ENABLE Input
Enable Input Logic-Low
Voltage
VIL
Regulator shutdown
Enable Input Logic-High
Voltage
VIH
Regulator enabled
IIL
Enable Input Current
GM6155
IIH
4
VIL
0.4V
VIL
0.18V
VIH
2.0V
0.4
0.18
2.0
2
V
V
0.01
-1
-2
µA
5
20
25
µA
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3: The maximum allowable power dissipation at any TA (ambient temperature) is PD(max) = (TJ(max) -TA) qJA. Exceeding the maximum
allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.
Note 4: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 5: Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the
load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 6: Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at
1V differential.
Note 7: Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the
sum of the load current plus the ground pin current.
Note 8: Thermal regulation is defined as the change in output voltage at a time "t" after a change in power dissipation is applied, excluding load
or line regulation effects. Specifications are for a 150mA load pulse at VIN = 16V for t = 10ms.
Applications Information
Enable/ Shutdown
Forcing EN (enable/ shutdown) high (>2V) enables the regulator. EN is compatible with CMOS logic gates. If
enable shutdown feature is not required, connect EN (pin 3) to IN (supply input, pin 1). See Figure 3.
Input Capacitor
A 1µF capacitor should be placed from IN to GND if there is more than 10 inches of wire between the input
and the acfilter capacitor or if a battery is used as the input .
Reference Bypass Capacitor
BYP (reference bypass) is connected to the internal voltage reference. A 470pF capacitor (CBYP) connected
from BYP to GND quiets this reference, providing a significant reduction in output noise. CBYP reduces the
regulator phase margin, when using CBYP, output capacitors of 2.2µF or greater are generally required to
maintain stability.
The start-up speed of GM6155 is inversely proportional to the size of the reference bypass capacitor.
Applications requiring a slow ramp-up of output voltage should consider larger values of CBYP. Likewise, if
rapid turn-on is necessary, consider omitting CBYP.
If output noise is not a major concern, omit CBYP and leave BYP open.
Output Capacitor
An output capacitor required between OUT and GND to prevent oscillation. The minimum size of the output
capacitor is dependent upon whether a reference bypass capacitor is used. 1.0µF minimum is recommended
when CBYP is not used (see Figure 2). 2.2µF minimum is recommended when CBYP is 470pF (see Figure 1).
Larger values improve the regulator's transient response, the output capacitor value may be increased
without limit.
The output capacitor should have an ESR (effective series resistance) of about 5W or less and a resonant
frequency above 1MHz. Ultra-low-ESR capacitors can cause a low amplitude oscillation on the output and/
or underdamped transient response. Most tantalum or aluminum electrolytic capacitors are adequate; film
types will work, but more expensive. Since many aluminum electrolytics have electrolytes that freeze at
about -30°C, solid tantalums ate recommended for operation below -25°C.
At lower values for output current, less output capacitance is required for output stability. The capacitor can
be reduced to 0.47µF for current below 10mA or 0.33µF for current below 1mA.
No-Load Stability
GM6155 will remain stable and in regulation with no load (other than the internal voltage divider) unlike
many other voltage regulators. This is especially important in CMOS RAM keep-alive applications.
Thermal Considerations
Gm6155 is designed to provide 150mA of continuous current in a very small package. Maximum power
dissipation can be calculated based on the output current and the voltage drop across the part. To determine
the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the device
and the following basic equation:
PD(max) =
(TJ(max) - TA)
RqJA
GM6155
TJ(max) is the maximum junction temperature of the die, 125°C, and TA is the ambient operating temperature.
RqJA is layout dependent; Table 1 shows examples of junction-to-ambient thermal resistance for the GM6155.
5
Parameter
RqJA Recommended
Minimum Footprint
RqJA 1" Square
220°C/ W
170°C/ W
SOT-23-5
RqJC
Copper Clad
130°C/ W
Table 1. SOT-25 Thermal Resistance
The actual power dissipation of the regulator circuit can be determined by using the equation:
PD = (VIN - VOUT) IOUT + VIN IGND
Substituting PD(max) for PD and solving for the operating conditions that are critical to the application will give
the maximum operating conditions for the regulator circuit. For example, when operating Gm6155 at room
temperature with a minimum footprint layout, the maximum input voltage for a set output current can be
determined as follows:
(125°C - 25°C)
PD(max) =
220°C/W
PD(max) = 455mW
The junction-to-ambient thermal resistance for the minimum footprint is 220°C/ W, from Table 1. The maximum
power dissipation must not be exceeded for proper operation. Using the output voltage of 3.3V and an output
current of 150mA, the maximum input voltage can be determined. From the Electrical Characteristics table, the
maximum ground current for150mA output current is 2500µA or 2.5mA.
455mW = (VIN - 3.3V) 150mA + VIN • 2.5mA
455mW = VIN • 150mA - 495mA + VIN • 2.5mA
950mW = VIN • 152.5mA
VIN(max) = 6.23V
Therefore, a 3.3V application at 150mA of output current can accept a maximum input voltage of 6.2V in a
SOT-25 package. For a full discussion of heat sinking and thermal effects on voltage regulators.
Fixed Regulator Applications
1
2
3
5
Figure 4. Low-Noise Fixed Voltage Application
VOUT
VIN
2.2µF
2
Enable
Shutdown
4
GM6155
470pF
6
Figure 3. includes a 470pF capacitor for low-noise
operation and shows EN (pin 3) connected to IN (pin 1)
for an application where enable/ shutdown is not
required. COUT = 2.2µF minimum.
1
3
GM6155
VIN
GM6155
Figure 3. Ultra-Low-Noise Fixed Voltage Application
5
VOUT
1.0µF
4
EN
Figure 4. is an example of a low-noise configuration
where CBYP is not required. C OUT = 1µF minimum.
Adjustable Regulator Applications
The GM6155 can be adjusted to a specific output voltage by using two externa resistors (Figure 5). The resistors set the
output voltage based on the following equation:
VOUT = 1.242V X (
R2
+1)
R1
VIN
1
2
3
GM6155-Adj
This equation is correct due to the configuration of the bandgap reference. The bandgap voltage is relative to
the output, as seen in the block diagram. Traditional regulators normally have the reference voltage relative to
ground and have a different VOUT equation.
Resistor values are not critical because ADJ(adjust) has a high input impedance, but for best results use
resistors of 470kW or less for best results. A capacitor from ADJ to ground provides greatly improved noise
performance.
VOUT
5
2.2µF
R1
4
R2
470pF
Figure 5. Ultra-Low- Noise Adjustable Voltage Application
Figure 5 includes the optional 470pF noise bypass capacitor from ADJ to GND to reduce output noise.
Dual-Supply Operation
When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage
Typical Characteristics
0 V = 6V
IN
VOUT = 5V
0 V = 6V
IN
VOUT = 5V
-20
PSRR (dB)
-40
-60
-80
IOUT =100mA
COUT = 1µF
100
1k
10k
100k
1M
-100
10
10M
IOUT =100mA
COUT = 2.2µF
CBYP = 0.01µF
100
1k
10k
100k
1M
10M
FREQUENCY(Hz)
FREQUENCY(Hz)
Figure 6. Power Supply Rejection Ratio
Figure 7. Power Supply Rejection Ratio
320
10
280
125°C
1
240
200
NOISE (µV/ Hz)
DROPOUT VOLTAGE (mV)
-60
-80
-100
10
25°C
160
-40°C
120
80
40
0
0
-40
40
80
120
OUTPUT CURRENT (mA)
Figure 8. Dropout Voltage vs.
Output Current
160
100mA
0.1
10mA
0.01
VOUT=5V
0.001 COUT=10µF
electrolytic
C
=10nF
0.0001 BYP
10
100
1k
1mA
10k
100k
1M
FREQUENCY(Hz)
Figure 9. Noise Performance
10M
GM6155
PSRR (dB)
-20
7
SOT-25(SOT-23-5) PACKAGE OUTLINE DIMENSIONS
2.9 ± 0.1
1.9 ± 0.05
0.13
0.95 ± 0.038
Pad Layout
0.028
0.7
0~0.1
1.5 ± 0.05
0.039
1.0
2.8 ± 0.1
0.094
2.4
0.65 ± 0.05
0.8 ± 0.05
0.35 ± 0.03
0.037
0.95
5°
0.037
0.95
0.074
1.9
5°
1.10 ± 0.1
Unit:mm
ORDERING NUMBER
GM 6155 A ST25 R
Gamma Micro.
Shipping
R: Tape & Reel
GM6155
Circuit Type
8
Output Voltage
A: Adj, 2.5: 2.5V
2.7: 2.7V, 2.8: 2.8V
2.9: 2.9V, 3.0: 3.0V
3.3: 3.3V, 3.6: 3.6V
4.0: 4.0V, 4.2: 4.2V
Package
ST25: SOT-25
( Inches
mm )
9
GM6155